Question: Worms were eating the leaves on my two red oaks. Several limbs are bare. Have the worms killed the branches? What insecticide do you recommend? I have a small dog that uses the back yard. Will insecticide hurt him? R.A., Dallas
Answer: I don't recommend anything that hurts dogs. That's one of the many benefits of an organic program. Many worms attack trees. Forest tent caterpillars, for example, are pests that occur in late spring or early summer. They generally are more cosmetic than destructive. Canker worms hang from threads, while other worms eat or roll up leaves.
The control of these larvae of moths and butterflies is the same. Release trichogramma wasps as the leaves start to emerge in the spring. As a last resort, spray Bt (Bacillus thuringiensis) at dusk according to label directions. Add 1 tablespoon of molasses per gallon of mix.
Caterpillars also can be killed with sprays of plant oils or mound drench mixtures of orange oil, compost tea and molasses. Products that contain Spinosad also work. Your trees will be slightly stressed, but they should rebound.
Question: A horse stripped the bark off my 3-year-old peach tree. I wrapped a feed sack around it until the bark grew back. Then goats got into the garden and almost ate the tree, so I put pine tar on the wounds. Despite all this, the little tree is loaded with peaches. Borers are attacking it now, but I don't want to put chemicals on it. I also don't want this strong little tree to die. S.D., Colleyville
Answer: You have already used toxic chemicals. Try to get the pine tar off the tree and apply my Sick Tree Treatment. Follow my recipe for making Tree Trunk Goop and apply it to the wounds instead. (To obtain recipes, see Resources box.) Applying full-strength orange oil will kill the borers.
Question: I have a problem with wasps hovering constantly in my oak trees and would like to know how to get rid of them.I have pets and do not want to use a chemical if I didn't need to. J.P., Dallas
Answer: Wasps are beneficial and not aggressive when they are foraging, so I don't recommend doing anything. Garlic spray probably will repel them if you want to do something.
Question: I am deploying overseas with the military, and I received six packages of insect and arthropod repellent. I am supposed to wash my uniforms in this stuff. Active ingredients: permethrin 40 percent, inert 60 percent. It doesn't sound health-inducing. R.C., Fort Hood
Answer: That is a synthetic pyrethroid. I am not sure what you can do, but a vanilla and orange oil mixture would certainly be better.
Question: I've been told that I should apply humates to my sandy soil. What do you think? D.S., Hart
Answer: I think most humate products are good, but I also would use compost, compost tea and dry molasses.
Question: When is the latest I can spray for ball moss? Does sodium bicarbonate burn new plant growth after the temperature outdoors reaches a certain point?R.B., Dallas
Answer: It's probably too late to spray for moss without damaging plants since the leaves have emerged. Baking soda and potassium bicarbonate will be phototoxic at some point after temperatures rise. The best time for application is fall and winter. I'd suggest waiting until then to spray.