Good growing conditions this spring have also created a friendly environment for many landscape and garden pests. Just this month, Skip Richter with AgriLife Extension in Travis County had an article in “Texas Gardener” that included some low impact sprays for controlling some of those pests we encounter each spring. Following is a brief description of those sprays listed in order of importance to have on the garden shed shelf:
Insecticidal soap: Works well against small, soft-bodied pests such as aphids and mites. Once it dries, it no longer kills pests. Follow label instructions carefully as it can burn sensitive plants especially if mixed too strong or applied in hot, sunny weather. Repeated applications will reduce yields of some vegetable plants, so don’t overuse it.
Horticultural oil: Works well on aphids, mites, scale, insect eggs and whiteflies. Follow label instructions and keep the spray mixed well as you apply it. Can also damage plants if not mixed and applied properly.
B.t. (Bacillus thuringiensis var. kurstaki): Kills caterpillars. This works best on young caterpillars, so don’t wait too long to make an application. Caterpillars must ingest the product to be killed. Be sure to use this product judiciously because it will kill those caterpillars that turn into beautiful butterflies.
Kaolin clay: A fine, clay powder used in food products, toothpaste and Kaopectate! When sprayed on plants it leaves a white residue that repels some types of insects and discourages egg laying. I put it on the list as research shows that it works to repel stink bugs if applied early on when the pests first arrive.
Potassium bicarbonate: Similar to baking soda (sodium bicarbonate) but more effective. Helps prevent some diseases of the foliage if applied prior to infection to protect foliage from disease spores. Repeat sprays are needed to maintain control. Not a panacea and results will vary with various foliage diseases.
Neem oil: Works well to prevent powdery mildew or to shut down an early infection of the disease. Also helps control some insects such as whiteflies, thrips and squash bugs to name a few. Be patient as the product works as an anti-feedant (appetite suppressant) and disrupts the developmental stages of affected pests. So in most cases the results are not immediately apparent.