ALLISON WATKINS: Veggies a challenge this summer

SAN ANGELO, Texas - I've received a lot of questions lately about struggling vegetable plants; the heat stress of summer is starting to take its toll. There are various issues that can come up this time of year, including insect pests, diseases and just plain old high temperatures.

Spider mites are a common pest in the hot summertime, and they are difficult to control. Keep a close eye on vegetable plants and try to catch insect problems early. Spider mites have natural enemies that will usually keep them under control, but certain conditions can allow them to become problematic.

First, they prefer a dry, dusty environment. Populations can be reduced by spraying a strong stream of either plain water or insecticidal soap on vegetable plants. Good coverage is important, especially on the undersides of leaves.

Second, spider mites can become problematic after application of broad spectrum insecticides. This can occur because the pesticide damages the population of natural enemies, and certain products can even speed up mite reproduction.

Carbaryl, trade name Sevin, is an example of a product that should not be used around spider mite infestations. Laboratory studies have shown that the mites reproduce faster when exposed to the product.

Keeping a vegetable garden going through the entire summer is challenging. For gardeners who are struggling to keep plants going, consider splitting up warm-season crop production into spring and fall time frames.

This just means starting as soon as possible in the spring, after the last frost, with large transplants to get as much produce as possible before the hot summer arrives. Then start over with new transplants in August, to get more produce before the first freeze comes (usually around mid-November).

Most gardeners think of fall gardening as cool-season crops only, such as spinach, lettuce and radishes. These are great to grow through fall and winter, but most warm-season crops such as tomatoes, squash and cucumbers can be planted in August and grown through fall and still produce well before freezing weather sets in.

It's generally easier to keep vegetables alive and productive in the spring and fall, when the climate is milder, than to try and keep them going through the hottest months of the year. It will require frequent, thorough irrigation to do so — and with current water restrictions in place, it's not feasible.

But for those who want to try to keep tomatoes and other vegetables going even through the stressful summer, it can be possible with enough water. Try catching rainwater, or using recycled water such as from doing dishes.

Allison Watkins is Texas A&M AgriLife Extension Service county extension agent for horticulture in Tom Green County. Contact her at

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