QUESTION: What kind of mulch should I use in a vegetable garden? I have pine needles, but I'm not sure whether they are appropriate for this use. T.A., Coppell
ANSWER: Pine needles are great mulch for a vegetable garden. Pine needles stay in place, protect the soil and break down relatively quickly to form humus on the soil surface.
QUESTION: The 3-year-old wisteria in my backyard has destroyed several fences, and I have tried to kill the plant for several years. The trunk is so large that I had to cut it with a chain saw. After I cut it down, the shrub regenerated. How can I kill wisteria? C.Q., Bedford
ANSWER: Drill holes in the wisteria's stump – the more holes the better – and fill them with molasses. Then cover the stump with five to seven sheets of newspaper. Wet the paper and cover it with about 6 inches of shredded native tree trimmings. Keep the stump covered and moisten the pile every few days until the stump decomposes. It could take a year or more for the stump to decompose depending on the health of the plant, the weather that occurs, and other factors.
QUESTION: What is a good replacement for the soon-to-be-discontinued herbicide MSMA (monosodium methanearsonate) for killing crabgrass and dallisgrass in lawns? L.L., Richardson
ANSWER: Anything would be better than spreading an arsenic compound on your property. The Environmental Protection Agency ruled in 2009 that the use of the post-emergent herbicide MSMA on residential properties and sports turf such as athletic fields must stop by Dec. 31. 2010. Other uses, except to kill weeds in cotton fields, must end by Dec. 31, 2013. One alternative is Garden Weasel AG Crabgrass Killer, which is an excellent organic herbicide. It kills crabgrass; clover; barren strawberry (Waldsteinia), also known as false strawberry or mock strawberry; Virginia buttonweed and other weeds. You may have trouble finding a good post-emergent product to control dallisgrass. Researchers at the University of Tennessee have said that MSMA was the best option for killing dallisgrass without destroying surrounding turf.
QUESTION: Can orange oil and neem oil be used together as a spray to kill whiteflies? R.P., Dallas
ANSWER: Yes, but all you really need is EcoSmart Flying Insect Killer.
QUESTION: I have a dwarf Japanese maple that was planted three years ago on the northeast side of my house next to a deck. Nursery employees told me to use Dyna-Gro Liquid Grow 7-9-5 as the main fertilizer and Dyna-Gro Pro-TeKt as a supplement to help prevent marginal leaf burn caused by wind. What do you recommend for fertilizing and to prevent leaf burn? I am new to organic gardening, a nd I also need to know whether I can spray Garrett Juice on the maple. The nursery said these trees are fragile. C.Q., Dallas
ANSWER: Dyna-Gro may be a very good synthetic fertilizer, but I don't recommend synthetic fertilizers. Make sure the tree's root flare is exposed, and use my Sick Tree Treatment and an organic fertilizer. I also don't recommend foliage-protection products because they seem to interfere with a plant's ability to manufacture food. If the tree has red foliage, the environmental situation you described will be very hard on it. Those trees need afternoon shade. A better tree would be the original Acer palmatum, which has green leaves. It is the toughest Japanese maple, and the leaves turn red in autumn. This is the mother plant from which many named cultivars were bred. Garrett Juice is safe for all plants. You may use it on the Japanese maple without concern. See my website, www.dirtdoctor.com, to obtain free instructions for the Sick Tree Treatment.
QUESTION: Last year, an infestation of pine bark beetles killed several of my pine trees. Because I love pines, I would like to plant more but of a pest-resistant variety. What do you recommend? Also, I mulched the wood from the dead pines. Is it OK to use the mulch on a garden path, or should I throw it away? V.R., Pasadena, Texas
ANSWER: It's fine to use the pine mulch in your yard. Two pines you might consider as replacements are Italian stone pine and Aleppo pine. They are beautiful and are easy to grow.