Q: Normally, I would leave beneficial insects alone. However, I'm extremely allergic to red wasps. How do I eliminate these wasps? G.R., Colleyville
A: I understand. I wish we could move them to my place; they eat lots of worms and other pests. When they must be killed, the essential-oil products work well and are nontoxic. Eco-SMART is one good brand.The other step I highly recommend is to paint eaves and porch and patio ceilings with the color called haint blue. It is a robin's-egg blue that, according to Southern tradition, discourages wasps from building nests on its surface. Every paint manufacturer sells a version of this color. See my website's newsletter archives and the library for more details on the subject.
Q: The pH in my garden is 7.0. I would like to lower it to 6.4 for my tomato plants. Is sulfur the best way to lower it? P.S., Southlake
A: It's OK if you use a very small amount, 2 pounds per 1,000 square feet, or so. Using a couple of ounces of apple cider vinegar per gallon of water also will lower the pH. On the other hand, a pH of 7 is fine for growing tomatoes. If you just add plenty of compost and rock minerals, the pH won't be a problem.
Q What is the best liquid soap to use in the organic herbicide recipe? D.L., Decatur
A: I use a product called BioWash. It's available online, but almost any liquid dish detergent works.
Q: One morning when I went out to check my garden, I found small snails on the lettuce and spinach. Are these snails destructive to the plants? If so, what should I do to control them? R.G., Porter
A: Dusting with food-grade diatomaceous earth, spraying essential oils and applying the commercial product Sluggo Plus all work. Start with the DE and work up.
Q: After I make compost tea, how long can it be stored in a plastic container? A.B., Frisco
A:It will retain its effectiveness quite a while, but the liquid will get clumpy because of microbe growth. This growth will be primarily bacteria, rather than fungi, and it will probably be anaerobic species because of being in a sealed container. Strain out the clumps, toss them into the compost pile, and use the rest for spraying and drenching. It will be effective but not as good as the fresh-made brew used immediately. Make a smaller batch, if possible.