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Landscape PlantsBermudagrass in Albuquerque?
Buffalograss seeds, watering
Bluestem grass, removing
Broom dalea at home
Broom (Spanish) pruning
Chinese pistache trees fall color
Datura and Trumpet Vine
Grass & drought
Grass dies in winter?
Grass not growing under trees
Grubs cause dead grass patches
High altitude groundcover and flowers
Hillside landscape plants
Italian Pines in New Mexico
Juniper pruning, spring is best
Landscape for family protection
Landscapes, NM & El Paso
Lawn grass choices
Lawn, soil amendments
Lawn, starting
Lawn, urine burn spots
Lawn yellow
Lilac, when to prune?
Lilac, when to re-plant
Lilac yellowing
Patio plants sunburned
Patio plants, winter protection
Propagating vines
Pruning hibiscus
Pruning, when?
Rainfall and Your NM Lawn
Removing old hedge roots
Rocky Mountain zinnia
Shallow-root plants
Spring clean-up
Virginia creeper, germinating
Virginia creeper worms
Vitex tree looks like marijuana
Water efficient and like bluegrass?
Which vines to use for privacy?
White-gray coating on grass
Why can you mow grass but not other plants?
Chinese pistache fall color
Q. I saw a very beautiful Chinese pistache tree but have noticed that other Chinese pistache trees are not as pretty as the one I saw this autumn. I want one, but I want to be certain that the one I plant will have good fall color. How do I get one with good color?
A. The best way to increase your chances of having good fall color in any plant is to purchase it in the autumn when you can see the color. Many plants do not look as good in a container as they will once planted in the landscape, but the potential fall color should be evident. Soil conditions and irrigation may also have an effect on color, but by choosing the plant in the fall you greatly increase your chances of having the fall color you desire.
Fall is also a good time for planting many trees and shrubs. For most of them, root growth occurs in the fall after the air has cooled and the leaves have fallen. The temperatures below the soil surface remain suitable for root growth for quite a while after treetops have become dormant.
Fall is a good time to plant your tree, and you can select your fall color. In northern New Mexico the time is drawing short, but from Central New Mexico (lower elevations) and southward there is still time.
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Grass not growing under trees
Q. I have a beautiful front yard that has three very BIG trees. The problem is that there is no grass under these trees. What type of seed should I plant and what other advice can you give me? Please help!
A. It is very difficult to grow grass under trees. In a forest there are few grasses, and those that are there do not form a nice carpet like a lawn under the trees. Trees are effective at intercepting the light needed by grass to grow. Even though there is light under the tree, the wavelengths of light most needed by the grass have been removed. The shade of buildings does not inhibit grass growth as well as tree shade because buildings do not extract specific wavelengths from the light. Trees also intercept the rainfall and divert much of it to the dripline of the tree where it is more useful to the tree and where there may be more light to allow grass growth. Nearer the trunk of the tree, inside the dripline, water deficits also limit grass growth.
For these reasons, if the tree creates a dense shade, it is best not to try to grow grass under the tree. In the densest part of the shade, mulch or flagstone paving, along with lawn chairs, are the best solution. Be careful not to damage tree roots when placing the flagstones. If there is sufficient light penetrating the tree’s foliage, it may be possible to grow some groundcover plants which are adapted to lower light levels.
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Grass--does it die in winter? 12-00
Q. Why does grass die in the winter?
A. This is an interesting question. I assume you are asking about lawn grasses, but first I want to discuss grasses in general. Some grasses are annual grasses. Some of these are common weeds; others are important crop plants such as corn and wheat. These annual grasses live for a single growing season and die. They are genetically programmed to die at the end of their growing season. Our common lawn grasses are usually perennial grasses. That means that they grow for several years.
However, during cold or dry weather, they may become dormant (or quiescent) and appear to have died. The crown of the plant (where the leaves and roots meet) remains alive but dormant. As long as the weather is unfavorable, they remain dormant. Our lawn grasses re-grow from the perennial crown. So, these haven’t really died.
Finally, some of our perennial grasses die during the winter. They are not supposed to die, but due to damage from insects in the autumn or improper irrigation in the winter, they die in the winter and cannot resume growth in the spring. This is often seen as dead spots in the lawn in the spring. Remember, the perennial grasses are alive in the winter and still need moisture. They don’t need to be irrigated as often as in the summer, but a good irrigation once a month is important if the soil is dry and there has been no rain.
Damage from white grub worms shows up most often in the spring as dead grass. Winter irrigation is important in this situation to protect grass which has been weakened by the grubs feeding on their roots. However, treatment with chemical insecticides or biological control agents to control grubs is necessary in the late summer and fall to prevent injury to the grass. Such treatments can help you avoid dead grass in the spring.
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Grass, drought effects 11-99
Q. If grass is deprived of water, does it really "die?"
A. Grass certainly looks dead after extended periods without water, but after it gets some water it seems to come back to life. Was it ever dead? Some grasses will rapidly die during periods of drought, but even these die by parts. Bluegrass is an example of grass which cannot survive extended periods without irrigation, such as is common here in New Mexico. After a week or less, depending on the time of year and previous moisture and health of the grass, the grass will begin to turn brown. The leaves will die as they turn brown (they are dead). However, the crown, that part that produces new leaves, survives longer.
As the drought progresses, some of the grass crowns will begin to die, but if water is supplied, some will have survived and regrow. At this point the grass will be sparse. If the drought persists even longer, all the crowns will die and only weeds or more drought resistant grass species will grow once water is supplied. Many of the warm season grasses we grow, such as bermuda grass, buffalo grass, and blue grama, are much more drought tolerant and will survive longer periods of drought. These are often the grasses that reappear after dry periods. There are other native grasses that also survive. Fescue, often used in lawns, is intermediate in response. It can tolerate somewhat more drying than the bluegrass but not as much as the drought tolerant grasses mentioned above.
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Grass has whitish-grayish coating
Q. I have several large areas in my back yard where a white/grayish fungus is on the grass blades. A couple of years ago a nursery suggested Daconil. When I used it the past two years, I don't think it spread very much but the Daconil, about the same color as the fungus itself, made that part of the lawn gray and did not clear up the problem. Recently I noticed the same spots re-occurring plus some other areas. This time the nursery recommends Sulfur Hydroxide. What is really best? Either of these, a combination of both, or something else? The grass is well established, probably about 35+ years old and is mainly a fescue. At least that is my estimation since the lawn was sowed by the previous owner as Albuquerque Mix.
A. I wonder if this is really a fungus. Powdery mildew makes a thin whitish coating on the leaves. Powdery mildew can be a significant problem, but can often be managed by reduced night humidity - irrigate early in the morning every third day or so. Some fungicides (labeled for treatment of powdery mildew) can also be used if irrigation scheduling changes can't eliminate the problem. Even so, irrigate in the morning and infrequently to keep the fungus from reappearing. If it is a thicker grayish coating on leaves of grass over an area less than a foot in diameter, it may be slime mold which is not a real problem and can be washed off with a strong stream of water. Slime mold should not damage the grass (except to exclude light from the coated leaf blades). The best way to know for sure is to take a sample of the affected grass to the County Extension office and have the agent determine what specific problem is present.
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Grubs cause dead grass patches
Q. I have found patches of dead grass. When digging at the edges of these areas of dead grass I found large white worms with brown heads. What are they and what should I do about them?
A. You have described white grubs. These are the larvae of the May beetle or June beetle. These are the light brown to honey colored beetles which fly around porch lights, street lamps, and other lights in late May and June. They also tend to make noise as they run into window screens when attracted to windows lit by interior lamps. You described their larvae and if you remember the beetles flying around last summer, that is extra confirmation that grubs are likely the problem. However, even if you don’t remember them, you probably have white grub problems based on your description. You can take a sample to your local NMSU Cooperative Extension Service office to confirm that you have collected grubs.
Another confirmation is the symptom you described, patches of dead grass. While other things can cause this symptom, the presence of the grubs at the edge, where the living and dead grass meet, makes it likely that grubs are responsible. Grubs eat the roots of the grass, causing the grass to die. With the roots removed, the grass can often be lifted from the soil like a rug. So, what should you do? At this time of the year you should do nothing.
The grubs are full grown and are not feeding much. They will soon pupate and begin the metamorphosis into June beetles. Because of their size and late pupal stage (just before pupation) they cannot be easily killed by pesticides. Besides, the damage that this generation will do has already been done. Yes, dead patches of grass are becoming apparent, but that is due to grub feeding when the grubs were smaller and more actively feeding. It is only just now appearing as the grass greens in the spring and as rising temperatures create and increased need for water which cannot be supplied by the limited root system left by the grubs.
In May and June the beetles will emerge from the soil, mate, and lay eggs. These eggs will hatch in late July and August. Once the eggs have hatched, you can treat with any of several insecticides labeled for use in managing lawn white grub problems. There is even a product which has a long residual duration in the soil so that its label recommends that you apply it in June, before the eggs hatch. However, most products should not be applied until mid-August (early August in the southern part of New Mexico). Contact your Cooperative Extension Service agent to determine which product you wish to use. Read the label on this and any pesticide before purchasing it to be sure it will do what you want and can be used in the type of grass, or other plants, you wish to use it. Be sure to follow the directions on the label carefully to maximize the benefits of the product.
If you wish to avoid the use of chemicals, there is a biological control method which employs parasitic nematodes, small worms which kill grubs. These can be mail ordered or in some cases purchased at local garden centers. Read and follow directions for the use of nematodes if you choose to use them.
The white grub so commonly written about in garden books and publications for the Mid-West and East are the larvae of the Japanese beetle. This is currently not a problem in New Mexico. Some products which are recommended for control of the Japanese beetle white grub, are not very effective in controlling the grubs common in New Mexico, so choose only products which are for white grub/June beetle control.
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High altitude groundcover, flowers for NM 4-01
Q. I can’t seem to find a sturdy flowering ground cover or flowering plants to grow at my house which is at an elevation of 8500 feet. I’ve spend hundreds of dollars on different plants, but lilac, raspberry bushes, and sumac are the only plants that made it through the snows.
A. Your elevation creates complications and opportunities. Some flowers that do well at lower, hotter elevations may do poorly under the conditions at your home, but there are plants that will do very well at higher locations. Besides being cooler and having more moisture at higher elevations, you are likely to have more shade from the trees common at higher elevations. The shade creates some benefits and liabilities of its own. If the shade is too dense, some thinning may be helpful. After last year’s fires, there is growing interest in thinning the forest around homes, creating better environments for landscape plants. Consider fire safety as you develop your landscape.
Now, plants for your area include many bulb plants, annual and biennial flowers that are grown in cooler climates, and perennial plants that will survive the winter. I will list a few of these, but there are many more. As you read books and magazines looking for others, remember that your soil may be too alkaline for some plants. A soil test will help you determine your exact soil pH and salt conditions. This knowledge will help you in making plant selections. You may need to create raised beds for some of these plants to have enough soil depth for them to grow well since soils are shallow in many high elevation locations. The bulb plants and some of the herbaceous perennials will need soil at least one or two feet deep. Bulbs to consider include: tulips, daffodils, grape hyacinths, crocuses, lilies and many others.
Some herbaceous perennials will also be good choices with the bulbs. These include: peonies, columbines, bleeding hearts, oriental poppies, some varieties of flowering sedums, and perhaps chrysanthemums. The daffodils seem to be more deer and rabbit repellant than some of the others, so you may need to provide some wildlife protection. Siberian squill is another flowering bulb that will be distasteful to wildlife. It is toxic to humans, so don’t use this one if you have children who might be tempted to eat them. (My children never had problems with this when they were young, but they were taught to ask before eating any plant in the garden.)
Many annuals and biennials will grow well under high elevation conditions if they receive adequate light. Some good choices include: pansies, johnny-jump-ups, sweet alyssum, marigolds, cosmos, calendulas, California poppies, Shirley poppies, sweet williams, foxgloves, and hollyhocks. Many of these will re-seed and return year after year. The choice of flowering groundcover plants may be somewhat more limited, but there are some choices. Vinca minor is a good choice for you. Rocky Mountain zinnia will die back each year, but return to create a colorful groundcover each summer. There are a variety of groundcover sedum plants which will flower. The alyssum mentioned earlier, although an annual, will return from seed each year and serve as a summer groundcover. California poppies, if grown densely, can also serve in this manner. This list is very limited, but shows some of the plants available to you.
Your elevation gives you many opportunities uncommon in for New Mexico. I’m sure you already enjoy the unique benefits of your location; now you can also enjoy the unique gardening benefits.
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Italian Pines in New Mexico
Q. I was told the beautiful pine trees that I saw in Italy would grow here in New Mexico. Is that true? I like their interesting umbrella shape.
A. The umbrella shape that you described is the form of the Italian stone pine, or Pinus pinea. This is a beautiful, fairly drought-tolerant pine tree that will grow in some parts of New Mexico. I have seen several growing and doing well in Albuquerque. However, in recent years several of these have been cut down.
It tolerates our soil, and with minimal irrigation it grows to produce a large attractive tree with a broad crown. If you want the umbrella-shaped form typical of the Appian Way trees in Italy and surrounding countries, pruning of lower branches may be necessary. In looking for information, I discovered that there is disagreement regarding the winter hardiness of this pine. One source said it was hardy only to USDA hardiness zone 8b, while the U. S. Forest Service information gave zone 7 as the hardiness limit. This may indicate that there are some trees hardier than others. This will depend on the seed source, so if you purchase one, ask for a tree from a northern seed source (northern Italy or Greece).
The Italian stone pine is one of approximately one dozen pine trees that produce pine nuts. I have not seen any mature nuts produced in Albuquerque, but there is a chance the nuts will mature in other parts of New Mexico.
This pine becomes rather large, so select a site that gives adequate room for both the top of the tree and its roots to spread.
The Forest Service information also mentioned that finding a source of this tree could be difficult. I have not seen it in New Mexico nurseries lately, but you should be able to find it or have a nursery order it for you.
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Juniper pruning, when? 9-00
Q. Can I prune my junipers now (early September)?
A. You may prune junipers now, but if the junipers are pruned extensively, winter damage may follow late pruning. The junipers will also not be able to cover any unsightly spots exposed by pruning now since they will not grow in the autumn and winter. If there are a few branches interfering with traffic or your management of other plants, prune the offending branches. Save the major pruning for spring.
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Landscape for family protection 11-02
Q. Please help! Our house is just off a curved road where people have lost control of their cars and left the road. I am afraid that a car traveling too fast will cross our lawn and crash into our little boy’s bedroom. Is it a better to build a hill of soil or plant a row of trees to stop cars?
A. It is a good idea to consider the landscape as an element to protect your family in a situation like this. A berm of soil could possibly cause a speeding car to become airborne and actually travel farther than if it stayed on the ground. A higher, steeper berm could cause injury to the driver and passengers of the car, possibly subjecting you to liability problems. Trees may also injure people in the car, so a row of trees may also be a bad choice. It takes a long time for trees to become large enough to provide protection.
A properly designed and maintained hedge would be a better choice. You might also want to combine this with a thick layer of gravel like that found on highways in mountainous regions. Deep beds of gravel are often found on curves at the bottom of steep grades to stop run-away trucks. If properly designed, the gravel bed may remove a lot of momentum from the car without causing it to flip over. Rows of hedges just behind the gravel bed would be an attractive "safety net" to provide a little more stopping power.
The hedge should consist of plants with many small stems rather than just a few stems. The many smaller stems will yield, keeping the passengers safe, but will also serve to greatly slow the car. The hedge’s height should be at least 4 feet so that the hedge doesn’t lift the car into the air like the berm of soil. A hedge will grow faster than a tree, so the protection will be available much sooner. The hedge can be used to screen the view of the gravel bed from the house so that you don’t see the gravel every time you look from a window. If there isn’t enough room for the gravel bed, the hedge is still a good option. Several rows of hedge will serve better than a single row.
As a final protection, if you think it is necessary, a row of tall planters just outside the house may help. You can build these from concrete road culverts placed vertically and filled with soil. By the time the car reaches this point, the planters should not be harmful to the people in the car, but they will provide that one last bit of protection for your house.
A last thought would be to move the child to a bedroom in another part of the house. This may not be possible, but it would provide much greater protection for your child. What we have described here may stop a car, but a runaway truck or bus may not be so easily stopped.
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Landscapes for southern NM & El Paso 5-01
Q. My husband would like to plant plants and groundcover in our front yard that uses little or no watering. Could you please suggest something and how to care for these plants? Almost everything that we have tried to plant has died. Your help would be greatly appreciated. I’m tired of having an UGLY yard!!
A. In your location it is difficult to have a landscape that uses no water, but one requiring little irrigation can be achieved. However, it will be necessary to irrigate for a while until the plants have become established. The length of the establishment time requiring irrigation varies from plant to plant and soil preparation factors but can be a year or more for trees. Some shrubs and perennials can establish more quickly. Use of mulch can also reduce the need for applied water. Another useful technique is the use of harvested water; that is, to direct roof run-off water from rains to the root zone of landscape plants.
It is important to discover why your earlier plantings have failed. Were they watered enough to allow them to establish themselves in the landscape? Were they appropriate plants? Are there weed control chemicals in the soil which are preventing their establishment? If there are persistent weed control chemicals in the soil, the problem can be solved but it will be difficult. To test for this potential problem, put some of your landscape soil in a flower pot and plant some bean and corn seeds (or some broad-leaf plant and a grass). If there are chemicals in the soil, characteristic symptoms should develop in the plants. Contact your local Cooperative Extension Service office with help if this is the problem.
Container-grown plants may be a solution. If the soil does not contain harmful chemicals, then proper plant selection, irrigation for establishment, mulching, and other good management techniques should be adequate to create an attractive landscape. Plants to consider are numerous, and I will list only a small selection here. Groundcover plants and lower-growing flowering plants to consider include: iceplant, Rocky Mountain zinnia, desert marigold, evening primrose, California poppy, Calylophus (sun drops), desert four o’clock, penstemons, and many others. Shrubs to consider are: Buddleia (butterfly bush), Leucophyllum (Texas sage), creosote bush (beautiful if irrigated only slightly), evergreen sumac, Texas mountain laurel, broom dalea (purple sage), hoary rosemary mint (very fragrant foliage), cliff fendlerbush, Ephedra (Mormon tea), Apache plume, Algerita, Artemisia sagebrush species, and many others. There are many shrubs that will grow well in your hot, dry location. Some will do very will with little more than harvested water once they are established.
There are also trees to consider. Some become large, others are small: New Mexico Buckeye, western soapberry, fragrant ash, mesquite, palo verde, desert willow, Emory oak (evergreen), Texas madrone (very beautiful bark), junipers, and many others. Don’t fail to consider ornamental grasses. These are not grown as a lawn but as attractive clumps of grass used like we use shrubs in the landscape. Many of these will require little or no water once established. Of course there are numerous succulent plants to consider. Succulent plants include: agave, nolina, yucca, and the cacti. The plants listed above should grow well in El Paso, West Texas, and southern New Mexico. Many of them will also grow in more northern parts of New Mexico and at higher elevation, but not all are adapted to the colder regions.
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Lawns and pet urine burned spots 3-01
Q. My lawn has urine spots from my two female dogs. My lawn is fescue. Is there any help?
A. There are things you can do. You may be able to reduce the severity of the problem, but you will probably not totally eliminate the problem as long as you have dogs. I won't recommend getting rid of the dogs - pets are important. First, let's consider the dogs. Give them lots of water to dilute the urine. This will help a little. However, while you can provide the water, you can probably do little to make them drink more. You should also visit with your pets' veterinarian regarding the dogs' diet. Perhaps the veterinarian can recommend something that will help alleviate the problem.
From the perspective of lawn management, there are some things you can do. If you can regularly wash down the area which the dogs prefer, you can help minimize the burning. Frequent light irrigations (in the area most used by the dogs) can also help with this. A handful of gypsum placed on the spots and watered is reputed to be helpful. The gypsum will adsorb some of the urine. Be careful not to heavily fertilize the areas that the dogs like. Fertilizer salts can increase the problem. Anything you do to maintain a healthy lawn is important. Healthy grass will better resist damage or more rapidly recover from the injury.
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Lawn grass choices 6-01
Q. I need information on recommended turf grass. I will use private well water from a shallow aquifer of the Rio Puerco near Cuba, NM. I heard that Blue Grass takes too much water. I want a grass that has a good appearance, low maintenance, and good ground coverage (sod). Someone told me about Fescue, either tall or red fescue. Please help. I am hoping for summer rains to help with seedling establishment.
A. It is important to consider the function of the grass when choosing a lawn grass. You provided some of this information, but there are other considerations. Is the purpose aesthetics? Soil stabilization? Athletic use (children and pets)? It is also important to consider the water available and to determine whether or not you have enough water to support the desired function of the lawn.
Athletic uses, play areas for children and runs for dogs will have the highest water needs. It will be important for them to grow rapidly to recover from damage which occurs during use. However, most home "athletic" uses don’t require large acreage so only a small portion of the landscape should be used to grow these grasses. Outside the heavy use areas, lower water demand grasses (slower growing) may be used. If the function of the grass is only aesthetics and/or soil stabilization, you can use the lower water demand grasses.
Kentucky bluegrass does have a high water requirement. However, most people over-water bluegrass because the planting site was not properly prepared. Fescue can get by on a little less water than Kentucky bluegrass if the planting site is prepared to allow deep root development. Buffalograss and blue grama grass have even lower water needs, but again good site preparation is essential. There are some newer grasses (Texas bluegrass and Turtle turf) that are intermediate in water needs. It is also possible to use other native grasses in the less manicured areas. They will be well adapted to low levels of irrigation and will look pretty good from a distance. They may be mowed a few times a summer to keep them shorter, or they may be allowed to grow and set seed. In all cases manicured lawn or native grass areas, good soil preparation makes a lot of difference.
The soil should be prepared by plowing or roto-tilling deeply to loosen the soil. Soil is compacted near homes by trucks and other building equipment which had been driven over the site. This compaction must be eliminated. Addition of organic matter in the form of compost (or manure only in the fall) helps grass seedlings to establish and helps keep the soil open. Peat moss or other materials may be used, but they are more expensive. The addition of organic matter will increase the effectiveness of monsoonal moisture in helping establish the seedlings. Don’t trust the rains for seedling establishment. They may help, but they may also be too infrequent for successful grass establishment. Be prepared to irrigate briefly several times a day when the seeds are first germinating (skipping an irrigation or two if it rains). The soil must not dry once the seeds have begun to germinate. Later, as the seedlings begin to develop and there is good coverage of the site by seedlings, the frequency of irrigation can decrease and the duration of each irrigation can increase to moisten the soil more deeply to encourage deep root development.
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Lawn, soil amendments 12-01
Q. I have a small front yard (30’x 50’). It faces south. For the last year it has been used as a parking lot. I would like to rototill in some leaves from my mulberry tree and some pecan shells. Would this be a good type of mulch? I plan on planting grass next spring.
A. When planting grass, it is a good idea to work organic matter into the soil. These materials, leaves and pecan shells, will help to loosen the soil to help the lawn. The "parking lot" has compacted the soil creating a need for the soil to be de-compacted. The pecan shells will be slow to decompose and will maintain a porous soil allowing water to permeate the soil. The leaves will decompose rapidly if kept moist (even in the winter). The humus formed by the leaves will serve as sponges and hold the water in the soil as well as helping keep the soil loose and aerated. Other organic materials may also be added to improve the characteristics of the soil and enhance grass development.
However, I do have a concern regarding your plans to rototill. Is the tree in the vicinity of this lawn area? Tree roots will extend beyond the ends of the branches and may be damaged by the work you do in preparing the soil for the lawn. There is a term "critical root radius" which defines the zone in which there should be no rototilling or trenching (any activity that injures the roots). This is calculated by measuring the diameter of the tree trunk in inches at chest height (about 4 feet above the ground), multiplying by 1.5, and reporting the results (critical root radius) in feet. So, a 4-inch diameter trunk has a critical root radius of 6 feet. Within six feet of the trunk, do not damage the tree’s roots. It is important that you do reduce the compaction of the soil by rototilling or digging, but avoid the critical root radius.
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Lawn, starting in compacted soil
Q. I plan to turn over the soil and plant a new lawn. The soil seems to be quite compacted. What should I add to loosen up the soil?
A. Addition of organic matter, in the form of well-decomposed compost, is a good way to open the soil when planting lawns or gardens. Manures may be used but may also cause a problem if the soil is high in salts. The manure will aggravate salt problems as it may also have a high salt content. Manures should be applied in the autumn before a moist winter which leaches the salts from the manure. Some winters, as we have recently experienced, may not provide sufficient moisture and even manure applied in the fall may cause problems. To determine the potential for problems by adding salt, submit a soil sample for soil testing. A soil test will report the level of salt currently present in your soil.
In New Mexico, one of the problems when establishing a new lawn is that the soil was compacted during construction of a home. During construction cement trucks, lumber trucks, pickup trucks, etc., were driven across and parked on the future lawn area. This compacted the soil, forcing out the air spaces which are important for root growth. The first and most important soil amendment in this case is air which may be added to the soil by rototilling to loosen the soil. If the soil has a high clay content, addition of organic matter at this time is beneficial in
helping improve the "structure" of the soil to help maintain good porosity of the soil. If the soil is sandy, compaction may or may not be as severe a problem, but the addition of organic matter is still beneficial, increasing the water-holding capacity of the soil.
For more detailed information regarding your area, contact your local Cooperative Extension Service office. They should have good information specifically for your area and can help you in collecting a soil sample so that you may have your soil tested.
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Lilac pruning - when to do it? 5-02
Q. Is it okay to prune my lilacs now? How should I prune them?
A. Yes, in all parts of New Mexico the lilacs have finished blooming, or will very soon. Once flowering is completed it is okay to prune the lilacs. If you wait until after late summer, you will remove next year’s flowers. Removing the old flower clusters by cutting back to the first branch producing leaves will make the plant look much neater and prevent the formation of seed capsules. This directs more growth and energy into growth and production of next year’s flowers. If some branches are leggy and unattractive, they may be removed at or near the ground level to encourage new, more vigorous growth. Branches that are in the way and suckers growing from the soil around the base of the lilac shrub may be removed. Proper pruning will encourage healthy growth and increased flowering.
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Lilac: what is best time to re-plant? 5-01
Q. When is the best time to replant a lilac bush? We recently moved from the country to town, and I would like to replant my lilac bushes.
A. The lilac is a vigorous shrub that will tolerate transplanting almost any time. The best time would be late winter just before it blooms. I have transplanted it here in the summer when it is very hot and dry, and it still grew. More important than the time is the condition of the plant being moved. A young sprout dug from near the base of the lilac will transplant easily. The mature shrub will be more difficult to transplant. If it is the mature shrub, fall or winter would be the best time to transplant it. If you have already dug your lilacs, plant them as soon as possible. If you must move them now, or never, move them now.
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Lilac yellowing 8-03
Q. I have a lilac bush that has (until the last week) looked "healthy." It now has yellowing leaves and looks like it is dying. I have a dog that sometimes urinates on it. Could this be the problem?
A. It is possible that the dog is causing some of the problem, but that would occur only on leaves in direct contact with the urine. Dogs are usually a greater problem with junipers and other small conifers, which are even more sensitive.
Another consideration is moisture and potential leaf diseases. How much do you irrigate? If often, the humidity around the shrub can allow leaf fungus to grow at night. There are several leaf fungi that can cause minor problems (early defoliation) and usually don't kill the plant. The other possibility is that the shrub is not getting enough water, but lilacs don't require a great amount of water. Water them deeply once or twice a month. Clay soils hold more water so they can be watered less often. Sandy soils are easier to water, but they hold less water and must be watered more often. Water slowly at the dripline and beyond the edge of the shrub so that water doesn't run-off over the soil surface but soaks into the soil. Continue this until the soil is moistened to a depth of two feet. You will need to probe the soil with a soil probe or dig a shallow hole a few hours after watering to determine how deeply a given irrigation moistens the soil. If the soil is moist to one-half foot, increase the irrigation time to four times what you had done previously.
Irrigate in the manner described above if you have been watering more often than this. If you have other plants (shallow rooted annuals), you may water them less deeply and more often, but avoid daily watering. The greater the time between irrigations, the less potential there is for diseases.
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Patio plants sunburned 8-01
Q. I recently landscaped my townhouse courtyard with pots of Pretoria Canna and Big Leaf Philodendrons. They were full, beautiful and blooming. I have no patio cover and the pots sit on Saltio tile because there is no dirt. I think the tile draws heat to the plants. I have sprayed them daily and watered them enough to keep moist. The leaves on the plants look burned, and the plants are not producing any new leaves. What do I need to do before I lose them completely?
A. The plants that you described are from understory locations in the tropics; that is, they are adapted to shade and have a really tough time with direct sun, especially in the Southwest United States. The heat does complicate things but is not the primary problem. The leaves are just sunburning. The solution is shade. Some trellises placed in five gallon buckets or large flower pots and positioned to shade the plants, especially from mid-day until late afternoon, will help. The trellises alone may make enough shade, but vines planted on them will help more. Be sure to choose vines adapted to full sunlight locations, or for immediate benefit use artificial plants on the trellises this year. Continue to provide adequate water and moisten the tiles during the day as you have been doing. The damaged leaves will not recover, but the plants should produce new leaves if they are not too severely damaged.
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Patio plants, winter protection 12-01
Q. We corresponded a little last summer regarding the tropical plants in my townhouse courtyard in Phoenix, AZ. You may recall that I was having problems with the leaves burning because the Saltillo tile drew heat into the courtyard and there was little or no shade. I took your advice and they survived. Now my problem is the cold. Because the plants are surrounded on all sides by either block walls or wood and because they sit on the tile, the area is very cold. We will have some temperatures below freezing this winter, and I don’t know what to do to keep them safe.
A. The safest course of action is to bring the plants indoors when freezing weather is likely. If this lasts for only a few days, the plants will not be harmed if they are kept in a dark room. If a prolonged stay indoors is necessary, place them in a brightly lit room, preferably near east- or south-facing windows. It is okay to return the plants outside when the days are warm, but bring them indoors if the nights will freeze. To make it easier to move the plants, larger potted plants may be placed on platforms with casters allowing them to be rolled in and out. This may also work for collections of smaller potted plants, reducing the number of in and out trips to move your plants. Remember to water the plants as they dry more quickly in the drier indoor environment.
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Plants for slopes 2-02
Q. What low-growing plants can I get in 1-gallon containers for a hillside landscape - something with a little color in it rather than just green that takes very little care? I figure that one is the golden tip juniper, but what others could I use? Also, where can I find pictures as to what they look like? In my location there is rain toward winter; it is hot in summer. The site receives some shade and some sun. I live in Zone 8.
A. There are a lot of plants to use in this setting. However, not knowing your soil conditions, I will give a general listing. The juniper can be a good choice. There are junipers available in a variety of heights, spreads, and winter colors. Some turn plum color in the winter, others are more bluish, and some may include yellow tones. By carefully arranging the junipers, you can have a variety of colors. There are other evergreen and deciduous plants as well as grasses that would be good plants for a sloping landscape. Vinca is a broadleaf evergreen with blue flowers in the summer. Various cotoneasters in a range of sizes can contribute. They will have small flowers in the spring, green leaves through the summer, but in the fall when the leaves drop, their red or blue-black fruit will add color to the landscape and attract birds.
Ornamental bunch grasses are also interesting, low maintenance additions to the landscape (sloping or not). Their summer color is various shades of green while in the winter they range from reddish brown to tan, gray, or even blonde . Bunch grasses are available in a wide range of heights, from a few inches to several feet. Their motion in the wind provides a dynamic addition to the landscape, and their seeds are often very attractive for birds. To make specific selections from these groups of plants, visit demonstration gardens and nurseries in your area. In these locations, you can see first-hand examples of the plants growing in your locale.
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Propagating Datura and Trumpet Vine
Q. I moved into a house that has a beautiful Datura and a bush/vine with orange trumpet-shaped flowers. Both have put out seeds, the Datura’s look like little pine cones and other plants look like green bananas. I would like to plant more of these around my house, what is the best way (and time) to propagate them? Will they grow from seed?
A. The datura, if it is datura, should grow well from seed. The datura seed pod is usually covered with spines, kind of like a little round porcupine. If that is what you have, let the pods mature and as they split open , collect the seed and plant them where you wish them to grow. You can also plant them in the garden and transplant them later. If this is the common "Sacred Datura" or "Angel Trumpet" it is also possible to propagate it from pieces of root. Dig some thick pieces of root that are three to four inches long and bury them shallowly where you wish the new plants to grow. This is probably best done in late winter just before the plants begin growth. Keep the root pieces slightly moist as they are beginning to grow. Just be aware that the plant (all parts) is toxic if ingested.
The other plants sounds like a trumpet vine which may also be propagated by root cuttings as described above, by cuttings, and most easily by "layering". To layer the plant, take a long stem, wound it by scratching the bark or slicing through the bark with a knife. Apply rooting hormone powder to the area of the wound, then bury the stem at that point. Use some metal wire or a heavy rock to help hold the vine in place. At this time, the stem which is still attached to the parent plant should begin producing roots at the point of the wound. In a few months it may be separated from the parent plant and transplanted to the site where it is to be grown. It is too late this year to try this, or at least too late to expect to transplant it this fall. You may begin the process and give it until late next spring to develop roots, or begin the process just before growth begins next spring.
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Propagating vines 5-02
Q. Could you please help me find some information on propagating vines, especially silverlace and honeysuckle. I’m trying for some shade. Any assistance is greatly appreciated.
A. The silverlace vine is supposed to be very easy to propagate by seeds, cutting, and division. The honeysuckle vine is a little more difficult. Both may be propagated by layering. Layering is the process where you bend the vine to the ground, slightly wound the stem by scratching one side with a knife (or even a fingernail). Apply some rooting hormone powder to the wounded area, then bury the wounded portion of the still-attached vine in the ground. Make a hole where you will bury the portion of the vine, and fill it with potting soil. Keep it moist and covered with mulch (a large rock will help hold the vine down at that point and serve as some mulch as well). After a few months, roots should have formed and the new plant may be cut from the parent and transplanted.
You may also propagate the silverlace vine by stem cuttings, treating them with rooting hormone, and putting them in pots or in the garden in an area kept moist. If you use pots, you can put them in a cold frame or plastic bag to keep humidity higher. If you are using a cold frame or plastic bag, keep them out of direct sunlight to avoid overheating. The silverlace vine may also be propagated in the early spring by dividing the clump in the same manner that you would divide shasta daisies.
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Pruning hibiscus 3-01
Q. Are outdoor hibiscus bushes supposed to be pruned on an annual basis? I would appreciate anything you can tell me in regard to the care of hibiscus. I got one for a gift in mid-May last year. I planted it, and it was beautiful and bloomed until late in the fall.
A. Hibiscus varieties that are commonly grown outside in most of New Mexico will die-back to the ground every winter and should be pruned back before growth begins in the spring. You can do it now, or you can wait. Since you are in Las Cruces, there is a chance that you have the tropical type of hibiscus seen in Hawaii and other tropical locations. This hibiscus may survive mild winters in New Mexico but will probably be frozen back to the ground or near the ground each winter. Wait until spring after new growth has begun to remove any dead or freeze-damaged branches and twigs. When very cold weather threatens, you may be able to protect the base of the tropical hibiscus by putting bags of dry leaves around the base of the plant to insulate it. Once the cold weather has passed, you can remove this mulch.
They may also be grown as potted plants in much of New Mexico. As potted shrubs, tropical hibiscus will need some pruning to keep their size manageable so that they may be moved indoors to a brightly lighted location in the winter or to a cool (near freezing to slightly below freezing) location where they may go dormant (leaves will fall) and survive the winter. If they are maintained dormant and cool through the winter, they will not need light until new growth begins in the spring. At that time, they will need a brightly lighted location until they can be moved outside after the chance of freezing has pasted.
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Pruning Spanish Broom
Q. My Spanish broom plant has become extremely large and is interfering with my driveway. Can I prune it? How? When?
A. This is a common problem. Spanish broom grows much larger than the space often allotted to it. You can prune it. I often see it pruned by shearing or just cutting back. When the Spanish broom is pruned in this manner, it produces a "broom" type re-growth at the point where it was cut. In time this re-growth often dies or declines and look unattractive. Rejuvenation pruning is a better way to prune Spanish broom. Rejuvenation pruning is accomplished by pruning one or a few of the main stems to within a few inches of the ground. This should be done before growth begins in the spring. The plant will respond by producing new stems from the base instead of the "broom" at the end of a pruned branch. These rejuvenated stems will bloom prolifically as they mature. You do not need to cut all the branches in a single year; instead, go through a three-or-four-year cycle of removing the oldest stems, a few each year. At the end of the cycle, you will be ready to remove those which re-grew after the process began, starting the cycle again. This is a good way to keep the plant size appropriate for the space allotted to it.
By the way, rejuvenation pruning is a good way to prune several commons shrubs. Lilacs and Forsythia also benefit from rejuvenation pruning but should not be pruned until later in the spring following their blossoming period. A number of plants used in xeriscape plantings can also be rejuvenated. These include: fernbush, chamisa, and other shrubs that produce multiple stems at the base. When planting shrubs, avoid size problems by choosing plants that fit the available space. Before buying the plant, learn how large it will become when mature.
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Pruning – when? 3-01
Q. I know the dormant season is the right time to prune most things but have read that I shouldn’t prune roses, grapes, and lilacs during cold weather. Why?
A. Roses and grapes may initiate growth too early and be damaged by freezing if they are pruned too early. Many people have pruned early and the roses have done well, but there are a lot of roses in New Mexico growing from only the root stock (once flowering each year) as a result of improper pruning timing. It is best to wait until about a month before the expected last frost to prune roses and grapes to reduce the risk. Lilacs (as well as forsythia and other early spring blooming shrubs) produce their flower buds in the late summer. These buds will bloom as soon as growth begins in the spring unless we cut them off. Pruning during the dormant season removes the flower buds before blooming. New flower buds will not be produced until the following summer, so you will have a spring without flowers. It won’t hurt the plant; it will only prevent flowering.
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Rainfall and your NM lawn 7-99
Q. We have begun to get some rain. Can I stop watering my lawn at least for a week or so?
A. Whether or not you need to continue to irrigate your lawn depends on how much water the soil in your lawn has absorbed. If the rain falls rapidly and run-off occurs, then there was little water absorbed into the soil. This will be worse if the ground is not level and the water easily runs off. You should check the depth of moist soil to determine if you need to irrigate. Use a long screw driver, shovel, or other metal probe to test soil for soil moisture. If the soil is moist six or more inches deep, the probe will penetrate the soil easily to the depth of the moist soil. If the soil is moist to a depth of at least four inches, you can dispense with irrigation for that day. If you have an automatic irrigation system that runs regularly and keeps the soil moist, it would be wise to skip one or two irrigations.
From this, don't think that four inches is the ideal depth of irrigation. Grass roots can reach greater depths in properly prepared soil (by rototilling deeply). The greater the depth of roots in the soil, the more efficiently you may irrigate and the less subject the root system is to drying and temperature damage.
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Removing bluestem grass 10-02
Q. I have a lot of bluestem grass in my yard this year, more than ever. How can I get rid of it without killing my good grass? I cut it down, and the next day it is up again waving in the wind.
A. It is interesting that you have a problem with bluestem. We are recommending Little Bluestem as an ornamental (un-mowed) grass in landscapes in New Mexico because it is so well adapted and attractive. However, I can see where it can be a problem. Mowing will not eliminate it quickly. If it is mowed frequently to a short height and the surrounding lawn is in good health, the lawn grass should eventually overwhelm the bluestem. However, quicker ways to remove it include digging (a lot of work) or spot applications of herbicide.
If you choose to use herbicides, it is important to be very careful because you are trying to kill grass growing in grass you don’t want to kill. Choose an herbicide labeled to kill grass. Roundup® (glyphosate salt) is an example. It may be applied to the leaves of the bluestem by spraying or by brushing (painting) it on. Spraying will probably kill a spot of the desired lawn grass around the target bluestem. By brushing it on (diluted to the label recommended concentration), you can target the taller bluestem grass without harming the lawn grass. There are special applicators made for "wick" or "brush-on" application. These often have a tube containing the herbicide with a sponge or other absorbent material at the base. The sponge becomes moistened by the herbicide that is then transferred to the grass blades as you wipe the sponge across the grass. Take care to prevent dripping, or the lawn will be injured.
If you don’t need to treat a large area or don’t want to purchase the special applicator (or can’t find one), you can use a sponge and a small container of diluted herbicide. Be sure to wear new (without holes) plastic or rubber gloves. Disposable gloves may be used and then discarded after use. Follow the directions that come with the herbicide you choose to maximize the effect. Some of the bluestem may need to be treated more than once.
The reason this works is that some herbicides are absorbed by green tissues of the plant and translocated throughout the plant. Some of these (like the glyphosate mentioned as an example) cannot be taken up from the roots, so surrounding plants are not injured and there is no residue left in the soil to injure plants later. Since the bluestem stands above the other grasses, it is easy to target them while protecting the desired lawn grass. Once the bluestem grass has become dormant, you must wait until next year; however, if it is still green, autumn is the best time to treat it.
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Removing old hedge roots 10-02
Q. What is the easiest way to remove roots from a large hedge that has been in this location for 10 to 15 years? Would you recommend poison (DDT) or drilling/grinding/digging roots away?
A. The method used to remove the roots from a long-established hedge depends on the type of plants and the nature of their roots. It is a good idea to remove them if the roots are very large and from a plant likely to sprout from the roots. You may find it just as effective to dig up the stumps and large roots surrounding them with a shovel or backhoe. Finer roots systems or roots that will not sprout may be left to rot in place unless the site is needed for planning. Even then, only digging in the area needed to plant the new hedge or flowers must be cleared of roots. An herbicide may be used but should be used carefully and according to the label directions. Roots may remain for a few years. Even then, the roots will remain in the soil and interfere with new planting. By the way, DDT was an insecticide, so it would not have killed the plants even when it was available. However, DDT is no longer available and is illegal to use. Perhaps you meant 2,4-D. This herbicide would work, but it may create difficulties if you apply it to the soil and if you plan to plant a new hedge in the same location. That is why it is important to read the label directions and follow them closely.
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Spring clean-up
Q. Should I cut back or pull up last year’s mums and snapdragons? Last year I had grub worms in my fescue lawn. Do I need to spray again this year before replacing grass?
A. The chrysanthemums are perennials and should be alive below ground. Cutting the tops back before new growth begins is good. It was okay to leave the dead tops in place during the winter because they collect snow to moisten the soil around the roots. They also slow the wind over the plant crown, reducing evaporation. However, there is a slight chance that they can be a source of disease entry into the plants once the weather warms and growth begins. The dead stems are also unattractive so the planting will look neater if these dead stems are removed. Cut them with sharp pruning shears; don’t try to pull them out.
The snapdragons may have survived the winter, but they may also have died. Cut the tops back before growth resumes, if it resumes. You may find that seeds which fell from the plants have germinated, so even if the old plants didn’t survive, you may have new plants to replace them. If the old plants did survive, they can have problems with rust fungus in their second year so some gardeners dispose of them and don’t leave them. They either rely on the newly developing seedlings or they buy new plants. As stated before, if you want to leave the plants, cut the dead tops off with sharp pruners; don’t try to pull them off.
Finally, regarding the grub problem, you may need to spray again, but this should be done in early August if you are using most traditional grub control chemicals. Do this only if you find grubs in the lawn. To directly answer your question, no you don’t need to treat with chemicals before replacing the fescue, but you may need to treat afterwards. The grubs should do relatively little feeding in the spring before they pupate. Once they pupate (begin the metamorphosis from grub to beetle) they will not eat. It is the newly hatched grubs in August that may damage your replanted fescue.
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Virginia creeper, germinating 10-00
Q. How does a person germinate seed for a Virginia creeper vine?
A. Seed of the Virginia creeper may be germinated by planting them in the fall or by stratifying them in moist vermiculite or peat moss for eight weeks in a refrigerator at 40 degrees before planting them outdoors or in pots. The required cold exposure is usually provided by the winter temperatures if the seed are planted outdoors, but you can speed germination by storing them in moist vermiculite or peat moss in the refrigerator for a while before planting. They may be kept in plastic bags, or any other sealed containers, so that they do not dry while in the refrigerator. This "stratification" treatment is standard practice for seeds of plants from temperate climates. Under natural conditions, they must over-winter before they will germinate. We must provide conditions to simulate winter conditions before they will germinate. Tropical plants, on the other hand, do not have this requirement for germination.
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Virginia creeper worms
Q. There are some small worms eating the leaves off my Virginia creeper. These worms are yellow with black and blue bands. When they eat the leaves, they leave behind what looks like a net.
A. You have described the appearance and the damage done by the Western grapeleaf skeletonizer. This is the caterpillar of a dark gray or metallic blue moth with a one inch wing span. The adults lay eggs in clusters on the leaves. As the eggs hatch, the caterpillars begin eating the leaf tissue between the veins on the underside of the leaves. The tougher veins are left behind, creating the net-like skeleton that you described. These colorful caterpillars ultimately reach a length of almost one inch. Though this insect is called the grapeleaf skeletonizer, it can also attack Virginia creeper and Boston ivy, two ornamental vines which are related to the grapes. Since they are larvae of moths, they may be treated with Bt if you think they are doing sufficient damage to warrant control. Bt is the toxin produced by the bacterium, Bacillus thuringiensis. It may be purchased as a powder or liquid to apply to your plants. It is not toxic to humans, our pets, birds, and insects other than larvae of butterflies and moths. Other insecticides labeled for use on the affected plants may also be used. A warning: insecticides containing carbaryl can damage Virginia creeper and Boston ivy. Be sure to use any products according to their directions to maximize both safety and effectiveness.
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Vitex tree looks like marijuana 8-01
Q. Enclosed is a sample of a plant that has caused some controversy. Some people think that it is illegal. I know it's not but can't remember its name. What is this plant with a leaf that looks a little like marijuana?
A. The sample you sent, leaves with the suspicious look but strong smell, blue flowers, and seeds in a panicle is called the lilac chaste-tree, or vitex. Its scientific name is Vitex Agnus-castus. It is not illegal, it is not narcotic, but will probably give someone a terrible headache if they tried to smoke it. It is well-adapted to arid conditions (with limited supplemental watering). The flowers are attractive and produced over a long period in the early summer. The flowers can range from blue to pinkish to almost white. The plant can produce a small tree if pruned into tree form or can be allowed to grow as a shrub.
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Which vines to use for privacy? 7-02
Q. I would like to know what vines in my area would be good for an arbor I just put up - also something that would be pretty for my fence. I am trying to create privacy; however, I don’t want anything I cannot keep up with and control.
A. That’s a hard question because your taste in vines will be important in making the decision. Many people like trumpet vine because it attracts hummingbirds, but this is one that is hard to control. It will come up from "suckers" (root buds) some distance from the plant and may become more nuisance than benefit. Silverlace vine is fast growing, blooms with clusters of white flowers (bracts). It will need pruning back once it has reached the size you want. Most vines will need pruning to keep them in bounds. Honeysuckle is another one to consider but, in some moister parts of the country, it becomes weedy. It will need pruning.
Grapes are a good choice. They will produce edible fruit, and there is information regarding pruning available from your local Cooperative Extension Service office. Climbing roses may be a good choice. Clematis works in many cases. English ivy (evergreen), Boston ivy (deciduous), and Virginia creeper (deciduous) are other good choices. A visit to a local garden store to see what is available followed by a visit to the library to research the characteristics of each vine may be the best way to make your choice. The list is very extensive. (Here in Albuquerque my choice would be grape!)
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Yellow lawn
Q. We have fertilized and put iron on our lawn, but it gets yellower each day. The grasses are bermuda grass and fescue. We fertilized late in the spring and added iron last week. What else can we do?
A. A mixed cool season and warm season lawn creates some difficulties. The cool season fescue should receive less fertilization and be allowed go dormant in the heat of summer, while the bermuda grass needs to be fertilized and grows best in the hot weather. Keeping both healthy is difficult. Fertilizer needed by the bermuda creates increased disease susceptibility in the fescue when the weather is hot. Water management becomes especially critical. As far as fertilization, apply a light application of fertilizer to the bermuda grass once or twice a month through the summer. The most important constituent of the fertilizer for growing grass is nitrogen. Other nutrients are needed as well, but the nitrogen is needed in the greatest amounts. Apply fertilizer so that one-half pound of nitrogen is applied per 1000 square feet with each fertilization. If the fertilizer contains 10 percent nitrogen, you will need to apply 5 pounds of the fertilizer per 1000 square feet to achieve the rate of one-half pound nitrogen over this area. If the fertilizer contains 21 percent nitrogen, ammonium sulfate, then only a little less than two and one-half pounds of fertilizer will be needed for each 1000 square feet. That is calculated by dividing the one-half pound nitrogen needed by the percentage nitrogen in the fertilizer. Too little water will limit growth and health of the bermuda grass; too much water will favor fungal infection of the fescue. Irrigations which promote deep rooting of the grasses and drying of the grass crowns between irrigation will help prevent fungal attack while providing adequate moisture.
The frequency of irrigation will depend on soil type - sandy soils hold less water and need more frequent irrigation. It will also depend on the permeability of the soil and the depth to which moisture can penetrate. If the soil is compacted or has an impermeable caliche layer near the surface, it will not be possible to irrigate deeply enough to develop a deep root system to allow drying of the soil surface between irrigations. Soil preparation to provide a deep root zone is important. If the soil is not compacted, irrigate to moisten the soil to a depth of eight to twelve inches. Observe the grass to determine when irrigation is needed again. Rolling of the leaves, development of a grayish cast to the leaves, and persistence of footprints in the lawn are indicators that irrigation is necessary. Initially the grass may not have roots established in the full depth of soil which you are moistening, but the grass roots will develop to greater depth within a week or two, so continue modifying your irrigation regimen while the grass is developing its root system.
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Water efficient and like bluegrass? 1-03
Q. I plan to plant a new lawn this spring. At previous houses I owned, I planted blue grass because I like the color and texture. Obviously, bluegrass requires more water than other grasses. Is there another grass or grass mix you can recommend for this area that might have a similar appearance to bluegrass but requires less water? I have installed a sprinkling system so I will have water, but I would like to minimize the watering requirements. My soil is very sandy, though I plan on treating the soil with peat and possibly manure.
A. "Reville" Texas bluegrass is similar to Kentucky bluegrass but requires less water. There are other cool season grasses that will have similar appearance to Kentucky bluegrass. "Turtle turf" and lawn-type fescues are other options. Each uses less water than Kentucky bluegrass but more than a warm season grass.
Warm season grasses often do not have the appearance of bluegrass but can be attractive. These are the most water efficient grasses. They use less water during their growing season and much less water during their shorter growing season.
Your local Cooperative Extension Service agent can give you detailed information regarding the best grasses for your county. Your plan to amend the soil with organic matter is wise; however, there are some things to consider. Manures are often very salty and can damage germinating seeds. Composted manure is okay. Much of what is called "aged manure" has just been left in piles that were not turned or irrigated so they retain their salts. True composting will involve turning, addition of water, and usually other organic material. Use manure that has been properly composted.
Organic matter, whether composted manure or other compost, increases the soil's water-holding capacity and slowly releases nutrients that benefit the grass. The increased water-holding capacity increases the efficiency of irrigation by reducing the frequency of irrigation. The greatest evaporative loss of water with traditional sprinkler irrigation occurs during irrigation. That means that a soil that holds more water and can be irrigated less frequently can be watered more efficiently.
Another important consideration is that the soil be loosened as deeply as possible. Lawns planted near structures are often plagued with compacted soil that interferes with root penetration and water infiltration. When you incorporate the organic matter, you will be loosening the soil, so do this as deeply as your rototiller or spade will allow.
It is good to see people considering use of more water efficient grasses and proper soil preparation to conserve water. This will result in a more attractive lawn that requires less intervention on the part of the gardener to solve problems in the future.
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Native broom dalea at home? 2-03
Q. I have seen some grayish-green shrubs along the highway south of Albuquerque. Right now they just look like sticks, but last summer they had lots of small purple flowers. What is this? Are these plants available in the nurseries?
A. From your description, I think you have seen the plant called broom dalea (Psorothamnis scoporia). This is one of our native plants that is very well adapted to our hot, dry environment. Broom dalea grows in the deep sandy soils of the mesa regions around Albuquerque, northward to the Jemez and southward to El Paso. At maturity, it is often 3 feet high and 3 to 4 feet across. It is a useful plant in dry areas where it will receive little or no supplemental irrigation. In arroyos, its twiggy growth is good for slowing water flow and reducing erosion. Broom dalea grows best in deep, well-drained soils that are common to the mesas. It does not grow well in the valley soils if they contain clay and hold too much water.
Bees will actively forage broom dalea and produce an excellent honey. Flower production is greatest in years with good monsoon rains.
It is listed among the plants sold by some native plant and xeriscape-oriented nurseries. Call the nurseries to see if it is available.
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Rocky Mountain zinnia is compatible 2-03
Q. What is Rocky Mountain zinnia? Is it a good plant for New Mexico landscapes?
A. Rocky Mountain zinnia (also called Prairie or Plains zinnia) is a member of the daisy, or sunflower family that is very well adapted to our xeric gardening environment. Its scientific name is Zinnia grandiflora, so it is indeed a zinnia but not like the zinnia commonly sold as a garden plant. The Rocky Mountain zinnia is a perennial and doesn't need to be planted each year. It is not as subject to powdery mildew fungus problems and is much lower growing. Its flowers are yellow, small, and produced in large numbers in late spring, then it continues to produce scattered flowers through the summer until frost.
As a perennial, it has a tendency to spread but is not weedy. It needs very little water and will die if over-watered. This zinnia will grow best in well-drained soils. In winter, it turns brown and can be left in place to protect the soil from wind erosion. It may be trimmed back to near ground level before growth begins in the spring.
This is an excellent plant for our water conserving landscapes.
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Shallow-root plants 4-03
Q. I have a septic system in my back yard. I would like to plant some trees and shrubs. Can you give me a list of trees and shrubs that produce shallow roots so as not to affect my septic system? Please include native plants and trees in your list.
A. This is a common question that should be considered when septic systems are near plantings. There are "infiltrator systems," which may not be affected by plants, but the septic systems with a septic tank and leach lines may have problems. The primary problem is having roots enter the leach lines, clogging the lines. Planting above or near the septic tank may not cause a problem from the roots of the plants because this is a closed system that roots cannot easily enter. The problem with planting near the tank is that the septic tank is often near the surface, and the soil above it is not sufficient for plants other than grass. Also, it would not be wise to plant something that would interfere with the clean-out access to the tank.
There are almost no trees and shrubs that can be planted over a septic leach field without risk of clogging the system. There is too great a chance that their roots will invade the leach lines. If the leach lines are clogged, you will find it necessary to dig up the system and replace it, killing the trees and costing a lot of money.
Wildflowers, grasses, and other herbaceous plants are a better choice than trees and shrubs. Natives are good because you don't want to water an area in which the object is to dispose of septic system water. Native grasses, especially ornamental bunch grasses such as little bluestem, sheep fescue, blue avena, miscanthus species, and giant sacaton (quite tall), will be helpful in extracting the water without clogging the system. These may mix well with wildflower plants such as lupines, Indian paintbrush, Mexican hat, gloriosa daisies, butterfly weed (not really a weed), Russian sage, and many others.
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Is bermudagrass a good choice for Albuquerque? 6-03
Q. I read an article about bermudagrass and wondered if it was a good grass for me. I checked with some garden centers and couldn't find the seeds. If this is a good grass, where can I get seeds?
A. I relayed your question to Dr. Bernd Leinauer, NMSU Extension Turfgrass Specialist and Arden Baltensperger, NMSU Professor Emeritus. They have written the answer below:
The use of bermudagrass for home lawns in Albuquerque has generated interest after a recent magazine article on the breeding efforts in seeded turf type bermudagrasses at NMSU was published. From a purely aesthetic viewpoint, if tolerance to heavy traffic and recuperative ability during the winter months when the grass is dormant are not concerns, bermudagrass can be an acceptable low water use choice for home lawns. With the introduction of newly developed seeded turf-type cultivars such as NuMex Sahara or Princess 77, bermudagrass can be established and grown at a low cost in areas that were historically not considered suitable for bermudagrass.
Bermudagrass is a representative of the warm season grasses and is therefore much better adapted to the warmer desert climates than grasses such as Kentucky bluegrass or perennial ryegrass. As such, bermudagrass can be maintained at an adequate quality level with only 1 to 1.5 inches of water per week in the summer. However, the large water savings come from the winter months when only 1 or 2 irrigations are needed during the entire dormancy period. The use of bermudagrass for home lawns certainly makes sense from a water use point of view in periods of droughts, even in Albuquerque. During the summer, when bermudagrass grows actively, it is extremely wear-tolerant and recuperates well from traffic stress.
All these advantages, however, come at a cost for home gardeners and people who love their flowerbeds. Bermudagrass spreads aggressively by stolons (above ground runners) and rhizomes (below ground runners) and can become a nuisance when it invades flowerbeds and gardens. Also, periods of high temperatures that are conducive to growing bermudagrass may be limited to the 6 or 7 summer months, leaving the turf area dormant and brown for the remaining 5 to 6 months of the year. Furthermore, people allergic to bermudagrass may have to choose a different grass for medical reasons.
Sahara, the first seeded turf type bermudagrass was released 12 years ago from the breeding program at New Mexico State University and has been a big improvement in turf quality and texture compared to the much coarser common bermudagrass. Sahara is now being sold in southern New Mexico by large retailers such as Lowes and Home Depot making the seed easily accessible and lawn establishment affordable. Princess, the first seeded hybrid bermudagrass, was released 3 years ago by Seeds West in Arizona. Princess is considered a quantum leap in turfgrass breeding. It is not only the first seeded hybrid bermudagrass but it also combines texture, uniformity, and quality of the vegetative hybrid bermudagrasses (such as Tifgreen and Tifway) with affordability and the ease of establishment of seeded grasses.
The latest research from the University of Arizona has shown that Princess uses about 20% less water than Tifway to sustain the same quality level. Princess is not yet readily available in big retail stores. Curtis & Curtis, a seed retailer in Clovis, sells Princess and other seeded bermudagrasses in New Mexico, and these grasses can also be purchased on the Internet (e.g. www.seedland.com).
Note: Dr. Leinauer is conducting trials with both warm season and cool season turfgrass varieties in New Mexico. As information is developed and confirmed, Dr. Leinaur will release this information in NMSU Extension Service publications.
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Why water buffalograss seeds so much? 8-03
Q. I have planted buffalograss seeds. Why do I need to water several times a day? Isn’t buffalograss a drought tolerant grass?
A. Buffalograss is very well adapted to dry environments, but it needs water when the seeds are germinating. As the small seedling emerges from the seed, it is extremely dependent on water. After it has established itself and formed its crown (where the leave are formed and the bud is protected in the leaf bases), it can tolerate drought. Until that time, it will die if it dries.
If you plant buffalograss and natural rainfall maintains moisture in the top layers of soil in which the seeds are germinating, the grass does very well. This is the case when summer moisture is adequate (the monsoon provides moisture consistently). In dry summers such as we are experiencing this year, any buffalograss seeds that germinate in natural environments will probably dry and die. In our landscapes, if watering is permitted, we can establish buffalograss lawns. We must supplement the inadequate natural precipitation with frequent irrigation and/or mulch to keep the upper soil layers moist.
The mulch mentioned above is important. In nature, grasslands often have a mulch layer of old grass leaves. Grass seeds below the mulch layer may remain moist even if the monsoon doesn’t provide daily rain. Use of a thin straw mulch, or grass-clipping mulch, is helpful in establishing a lawn. As long as the mulch doesn’t shed water, creating a dry layer underneath, it reduces the required irrigation frequency and protects newly germinating seeds until the seedlings have emerged.
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Why can you mow grass but not other plants?
Q. It is obvious that grass is different from other plants because you can mow grass but cannot mow most other plants. What is the difference?
A. This is an interesting question related to plant anatomy. The grasses and many other plants called monocots differ from a separate group of plants called dicots in the manner in which growth occurs. The name monocot or dicot refers to the number of seed leaves (cotyledons) that develop when the seeds germinate.
Monocots have a single cotyledon while dicots have two cotyledons. Compare the single leaf-like coleoptile that appears when corn germinates to the two "seed leaves" when a bean germinates. However, this is not the only difference.
The place in a plant where new cells are produced is called the meristem. The production of new cells along with the enlargement of the new cells is the source of growth in size of a plant. The meristem of many monocots is in the "crown" of the plant right at the soil level. (In a palm, it is at the base of the leaf cluster at the top of the trunk.) The meristem of dicots is at the end of each shoot. (Roots of both dicots and monocots have meristematic regions at the end of each root.) Because the meristem is at the end of the twigs and branches in a dicot, if you "mow" the dicot, you cut off the source of growth and new growing points must emerge from buds along the stem. Dormant buds contain inactive meristems that begin growth when the buds above it are removed.
In monocots, since the growing point (meristem) is at ground level, you can cut the tips of the leaves and the meristem just continues producing new cells which enlarge and push the leaf blade up from the bottom. Therefore, you can mow the monocot grass but not the dicot.
This also explains the reason for careful pruning of dicots so that new growth from dormant buds is activated in the desired manner. This is a very limited discussion of a much more complex process, but I hope it helps you have a little better understanding of why you can mow grasses but not roses.
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