TREE TIPS AND MORE

by Curtis Smith, Ph.D.  

Q. I am considering replanting some 6-10 foot trees to replace some cedars destroyed by borers. I have three different types of trees I want to transplant - Arizona cedar, mulberry, and a type of desert "tree" much like a mimosa. When should I transplant, and what are the procedures? The soil in my area is basically clay with a layer of fine dust 2-6 inches deep. I've also been battling borers (little black beetle like bugs that start at the tip of the leaves on the cedars). They hollow out the twigs, kill the leaves. There is also a pest that eats the tree under the bark from the top of the tree down. It leaves a "swirly" design on the layer underneath with the bark peeling and falling to the ground. When should I start dosing the trees, and what should I use? Thank you for your suggestions.

Carey C.
Deming

A. I am familiar with the Arizona cypress (cedar?) and mulberry. I'm not sure which tree you are referring to as "much like a mimosa." In general, this should be a good time of year to plant trees. Prepare to plant by loosening the soil over a very large area (5 feet in diameter or more) for each tree if possible. Add organic matter (compost, etc.) to the whole area. It would be best to think that you are preparing a flowerbed in this area. In the center, plant the tree, digging no deeper than the depth of the rootball of the tree, or the depth of the root system if the tree is bareroot. It is important to plant on naturally compacted soil so that the tree doesn't sink when the soil settles. Planting too deep is not good for most of our trees. When you return the soil around the roots after planting, don't add any additional organic matter. This method of planting encourages the development of a good lateral (spreading) root system. Don't water more often than once a week in the beginning, twice a month after one or two years. When you irrigate, moisten the soil to a depth of two to three feet. Frequent watering will encourage a shallow root system that is not good for the tree. Cover the soil in the planting area with mulch (wood chips, straw, etc.) to help reduce weeds, reduce soil compaction, and conserve moisture. The black beetles you described sound like twig girdler beetles, or twig beetles. They can do damage to the tree, first at the ends of the branches then later, as the beetle population increases, at the trunk. It may be these beetles that are causing the "engravings" ("swirly designs"). It is also possible, if the engravings are fairly wide, that there are true borers also involved. A sample of the wood taken to your local Cooperative Extension Service office should allow the Extension agent to positively identify the pest so that proper control measures may be implemented.

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Q. I want to graft some new varieties on my old apple tree. When should I do the grafting? Can I just go to my friend who has another tree and take the grafting twigs the day I plan to do the grafting?

A. You will want to wait until the rootstock (the tree onto which you will be grafting) has begun growing. Depending on the style of grafting (or budding) you have chosen, it is best if the tree has begun growing and the cambium (region of dividing cells just under the bark) is actively dividing. However, it would be best to have the scion wood (the twigs to be grafted onto the tree) still dormant at the time of grafting. To have dormant scion wood, you should collect the twigs soon, store them wrapped in moist sphagnum moss in a refrigerator. Don't store them in the freezer. The time for grafting varies across the state and from year to year. Often the rootstock tree has begun growing when a period of cool weather interferes. Do not graft if there has been a recent cool spell. Wait until the weather has warmed for about a week before grafting following cool weather. This allows the cambium to become active again. It is also important that the soil be moist before grafting. Drought stress will also reduce cambial activity. The reason for so much concern about the cambium is that the cambium must be actively growing for the development of a successful graft union. There are several good books and some good web sites that illustrate different methods of grafting. Personally, I have been most successful using T-budding, but others I know are more successful with whip grafts and cleft grafts. You should look for a technique that works well for you. Grafting is the application of scientific principles but involves a great deal of skill.

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Q. I've been wondering what bug leaves eggs that look like cantaloupe seeds? They are laid in a neat row, layered over each other, and I have found them on my geraniums as well as on various garden plants, including my plum tree. Thank you. P.S. I enjoy your TV show every week.

Brenda L.
Valencia County

A. You have described katydid eggs. These are tan in color and usually placed in a double row of overlapping eggs. Here in New Mexico the katydid is not considered a significant problem. We consider it an interesting, green, grasshopper-like critter in the garden. So, in New Mexico, control is not usually necessary. In other parts of the country it can be a problem which requires some effort to manage. Be thankful that you are in New Mexico and can just enjoy the katydid.

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Q. What low-growing plants can I generally 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. Also, please join us on Southwest Yard & Garden, a weekly program made for gardeners in the Southwest. It airs on KRWG in Las Cruces Saturdays at 11:30 a.m., repeating Thursdays at 1:00 p.m.; on KENW in Portales on Saturdays at 10:00 a.m.; and on KNME in Albuquerque on Saturdays at 9:30 a.m. In next week 's show, Curtis Smith continues his tips on working with house plants, and John White shows us how to start tomato plants from seed, indoors.

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Q. A month ago I bought a Christmas Cactus. It was rather funny because I didn't know what it was and it didn't come with a name tag. So while I was searching the internet for another plant's name I didn't know, I came across this beautiful Christmas Cactus and I thought "Wow, so that's what it is!" I had wondered why it was in gold paper and on clearance at the end of January. Now the problem: it had a chunk missing at the base when I got it and now that area seems to be getting bigger and is getting mushy. I also noticed that roots seem to be developing between every section on the plant. Can I just cut them at the section and plant it? How do I save this plant?

A. The mushy area at the bottom sounds bad. Yes you can break (or cut) between segments and plant them. These segments are actually stem pieces (there are no leaves), so the segments will be stem cuttings which do root easily. I have had good luck planting them in cactus potting soil, in sand, and have even had roots form by placing them on moist sphagnum moss sealed in a re-sealable plastic bag. (Don't put the plastic bag in direct sunlight or it will overheat and cook the plant.) Once the plant has rooted well, it may be potted in the container in which you will be growing it. Use a well-drained potting soil. When taking the cuttings, I would make cuttings of the segments as far from the mushy area as possible. It is possible that the mushiness you described is due to bacterial infection that can spread rapidly and quickly kill the whole plant. Pieces close to the mushy area may already be infected, so the farther from the mushy area that you take cuttings, the better.

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Q. How close to a house foundation should mulch be spread?

A. This will depend on the type of mulch and potential pests. An organic mulch, such as bark mulch, close to a home can create problems with roaches if they are a problem in your area. Under plastic mulch (with rocks) we have seen carpenter ants that wandered into homes (probably not causing structural damage to the home). Other ants may also benefit from this, increasing their access to your home.

On the beneficial side, I think that a two-foot band of plastic mulch, covered by rock mulch to shed water from around a foundation can reduce potential termite problems by keeping the soil around a foundation dry (at least here in New Mexico where there is little soil moisture). If mulch is used in this manner, the flower bed and other plantings should be at least two feet from the foundation. If you have termite problems, plantings and organic mulch next to the foundation can exacerbate the problem. If termites are a potential problem in your area, application of a chemical termite barrier in the soil around your home before installing the mulch may be a good idea. Contact some pest control companies for estimates. This will depend on the type of mulch and potential pests. A bark mulch close to a home can create problems with roaches if they are a problem in your area. Under plastic mulch (with rocks) we have seen carpenter ants that wandered into homes (probably not causing structural damage to the home). Other ants may also benefit from this.

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Send your gardening questions to:
Yard and Garden, ATTN: Dr. Curtis Smith
NMSU Cooperative Extension Service
9301 Indian School Road, NE, Suite 112
Albuquerque, NM 87112

Curtis W. Smith, Ph.D., is a an Extension Horticulture Specialist with New Mexico State University's Cooperative Extension Service. Dr. Smith and Dr. George Dickerson host Southwest Yard & Garden, a weekly program for gardeners in the Southwest. It airs on KRWG in Las Cruces Saturdays at 11:30 a.m., repeating Thursdays at 1 p.m.; on KENW in Portales on Saturdays at 10 a.m.; and on KNME in Albuquerque on Saturdays at 9:30 a.m.