By August in Kansas, tomato plants are usually in full swing, but this year some Lawrence-area gardeners are seeing fewer tomatoes than usual. The weather is to blame for the limited fruit production, and there are only a few things gardeners can do to help their plants while waiting out the heat.

Two things happen to tomatoes when daytime temperatures stay above 95 degrees and nighttime temperatures stay above 75: Flowers pollinate poorly and fruit ripens slowly. The first, like the weather, is out of gardeners’ hands, but the key is to keep plants healthy so they can produce when conditions become favorable.

To keep tomato plants strong until slightly cooler weather arrives, check the soil moisture regularly and water deeply if needed. Drip irrigation or soaker hoses are best. If watering with a hose, avoid wetting the foliage or splashing any water upwards on the plant or fruit. Use straw, hay, or other mulch to insulate the soil surface and reduce water loss.

Pick any tomato fruits that have started showing color and bring them inside to finish ripening. Tomatoes ripen most quickly and with the best color development when temperatures are between 75 to 85 degrees, so place them in a warm spot in an air-conditioned home. If left on the vine in temperatures above 85 degrees, tomatoes may be paler than expected even if fully ripened and ripening time is extended without a benefit to flavor.

Create shade for plants if possible. In hotter locales, gardeners use shade cloth stretched over frames or lightweight row covers to create a little shade in the hottest parts of the day. Build the frame or set up the shade structure so that it only shades from the south, southwest or west (depending on the site) so that plants still receive full sun most of the day and are only protected from the most intense glares. For one or a few plants, a patio umbrella might even do the trick.

Monitor for pests and manage them if they appear to reduce stress on the plant. Flea beetles are especially bad this year. They are tiny, dark brown or black beetles that chew holes in the leaves and jump when disturbed. Row covers are good at preventing them, but once a crop is infested, they are difficult to control. Use yellow sticky cards and diatomaceous earth in organic gardens.

Spider mites also cause significant stress and thrive in hot weather. They are just big enough to see with the naked eye and feed on the undersides of leaves. Put a white piece of paper under a branch and shake the branch to check for presence of mites. If they are there, you will see the mites moving on the paper visible as tiny dark specks. Try hosing them off with a high pressure nozzle, or use horticultural oil or insecticidal soap according to label directions.

Larger pests such as blister beetles, hornworms and stinkbugs may come and go but do significant damage while present. Wear gloves and pick them off into a jar of soapy water if and when possible.

A few varieties of tomatoes are marketed as “heat-set” and are reported to perform better in high temperatures. Typically the difference is only a few degrees, but they may still set more fruit than traditional varieties in extended hot periods.

— Jennifer Smith is a former horticulture extension agent for K-State Research and Extension and horticulturist for Lawrence Parks and Recreation. She is the host of “The Garden Show.”