YOU ARE HERE: IVPress HomeCollections

Desert Gardener: Answering readers' questions

March 16, 2002|By Keith S. Mayberry, Imperial County-University of California adviser

QUESTION: I have some branches growing on my citrus tree that originate near the ground. They seem very vigorous. What should I do about them?

ANSWER: Cut off any branches that shoot up below the graft union on the truck. They may be crown or root suckers. The root stock material does not normally produce good edible fruit. In fact, root stock growth can be so vigorous it will take over the tree if not controlled.

Some gardeners like to remove the tips of long vigorous branches (above the graft union) to encourage the growth of lateral shoots to provide more shade and fruit on the tree.

QUESTION: I bought a tree, a bag of mulch and some fertilizer. I dug a hole 2 feet in diameter and 2 feet deep, put in the mulch, planted the tree and watered it every other day. Now the tree looks dead. What did I


do wrong?

ANSWER: It sounds like you killed your tree with misguided kindness.

First, the hole should be wide but not necessarily deep.

You need to dig some smaller drain holes deeper in the perimeter of the main hole (we use a 1-inch auger to do this), however there should be some more solid soil in the middle of the hole to keep the tree from settling too much. Then you should backfill the hole with a mixture of soil and mulch that contains no more than about 35 percent mulch. Pure mulch will act like sponge holding too much water. The mulch can sour and poison the tree roots. Next remove the air pockets by probing the backfill with a shovel handle to fill them in. Support the tree if needed. Then saturate the planting hole. Do not irrigate the tree again for at least three days. There is plenty of water to stimulate growth.

Overwatering runs all the air out of the ground and kills the tree roots. Fertilizer is not

needed until the roots are established and the tree starts making new growth. Then apply fertilizer sparingly. It may be necessary to either whitewash the trunk with white water-based latex paint or cover the trunk with aluminum foil to keep the trunk cool the first year of growth.

QUESTION: I have some peppers and tomatoes growing under a plastic tunnel. When should I take them out of the tunnel?

ANSWER: It is warm enough now to start to acclimate the plants to the outside temperature. Do not simply take off the plastic! The plants have been living in an environment of high humidity and high temperature. They need to adjust slowly to the change. Poke some silver dollar-sized holes in the plastic sheeting to let out some of the water vapor and heat. After a couple of days you can safely take off the plastic cover. If the covers are left on too long, the plants can suffer heat damage to the immature flowers causing malformed peppers and tomatoes.

QUESTION: I got some Indian laurel fig trees that do not grow very much. The leaves always look yellow on the edges and sometimes the very edges are burned. The trees look spindly. I fertilize and water them regularly. What am I doing wrong?

ANSWER: There is one problem that is common with Indian laurels. Often the bark near the base of the tree has

been scarred and damaged by string trimmers. This will cause damage to the food conducting vessels of the tree that lie just below the bark. Food manufactured in the leaves does not move to the roots and the tree starves to death!

Do not use string trimmers around soft bark trees. Also, Indian laurels do not generally do well in heavy clay soils where the roots cannot expand outward, such as in medians between the sidewalk and street. The laurels respond to regular irrigation but not to excess.

QUESTION: I sent my husband down to buy some tomato transplants. He came back with some plants that have stems that are nearly 8 inches tall. Can these still be used successfully?

ANSWER: Yes. You can remove a few leaves and then dig a shallow horizontal trench. Put the root ball in the ground and gently pull the transplant over and cover the stem with soil leaving a couple inches of the foliage sticking up. The stem will send out roots and anchor the plant. They should grow fine.

QUESTION: I never checked the ties on my trees and now some are growing into the trunk. What can I do?

ANSWER: There is not much that can be done once the string, plant tie or "wire" is trapped except to cut off the ends. The damage is done already. You can go around and make sure that none of the other tree ties are doing the same thing. Inspect the ties and loosen them as necessary every month or so, especially in spring and summer when the trunks are expanding rapidly.

Imperial Valley Press Online Articles