QUESTION: Should I prune apple and pear trees? K.B., Jacksboro
ANSWER: Apple and pear trees don't need much pruning. On apple trees, horizontal limbs and those growing at a 45-degree angle produce the most fruit. Pear trees are not as particular. You should basically remove dead wood and prune for appearance.
QUESTION: A disease called phytophthora killed the periwinkles in my garden. If I plant pansies in the same area, will the disease kill them, too? I have been using cypress mulch, in case that is an issue. J.J., Burleson
ANSWER: Healthy soil is the key to avoiding phytophthora and other diseases. Follow the instructions for bed preparation that are outlined on my website and switch to native cedar mulch. Cypress mulch does not break down well, it doesn't breathe well, and its harvesting and shipping create environmental problems.
QUESTION: I have noticed areas in my lawn where the St. Augustine grass turns light green and then yellow before ultimately dying. I have seen this happen to nearby lawns, too. What is the problem, and what can I do about it? For the past 10 years, I have been an organic gardener.M.R., Farmers Branch
ANSWER: The problem probably is a deficiency of trace minerals in the soil. Apply 50 pounds of zeolite per 1,000 square feet of lawn. Then drench the problem areas with Garrett Juice and Thrive. These liquids supply trace minerals, and zeolite will help balance and buffer the soil chemistry.
QUESTION: We recently bought a house that has 50-foot-tall cedar elms in the backyard. The trees are healthy, but I am concerned about their susceptibility to Dutch elm disease. What should I do to help the trees resist disease? S.S., Carrollton
ANSWER: Follow my Basic Organic Gardening Program. Native cedar elms are not very susceptible to Dutch elm disease, which is caused by a fungus spread by the elm bark beetle. Using organic fertilizers and amendments will create healthy biological activity in the root zone, so your trees should not be bothered by diseases. Two things to be aware of for cedar elm health are root flares and bad pruning. If the trees don't have exposed root flares, hire a certified arborist to use an Air-Spade to remove soil covering the root flares. Also, avoid overpruning. Cedar elms can be injured or killed by heavy pruning.
QUESTION: When should I replant asparagus plants and crape myrtles in southern Oklahoma? A.S., Calera, Okla.
ANSWER: Crape myrtles can be planted during fall and winter, and asparagus can be planted until February. Wait to move asparagus until after the foliage has been browned by a freeze. The asparagus should be moved to beds prepared organically using at least 6 inches of compost mixed with other organic amendments.
QUESTION: How important is it to apply pruning sealant to pruning cuts on trees? I don't like the way it looks, but I have been told that pruning sealant protects trees from insects and diseases. My trees recently were pruned. S.S., Plano
ANSWER: I don't recommend using pruning sealant. You can cover cuts and other wounds with my Tree Trunk Goop. To make Tree Trunk Goop, mix equal amounts of compost, natural diatomaceous earth and soft rock phosphate. Add enough water to this mixture to create a loose paste that can be smeared onto cuts, borer holes and other wood injuries. If dried goop is washed away by rain or irrigation, apply it again.
QUESTION: I have a question about cornhusks and corncobs. I have a 4-by-4-foot compost bin where I put straw and chicken waste for later use on an organic garden. We feed the chickens a lot of corn on the cob, but I'm not sure what to do with the cobs and husks. Neither seems to decompose in a compost bin. D.S., Dallas
ANSWER: Try to chop the cobs into small pieces before adding them to the compost pile, or crush them by laying them on a driveway and driving over them repeatedly with a car. You can cut the cornhusks into small pieces by spreading them out and going over them with a lawn mower. After adding corncobs and cornhusks to the compost pile, add dry molasses to stimulate and feed microorganisms. Adding up to 10 percent of the compost pile's volume in dry molasses is beneficial.