Southwestern Deserts

July, 2001
Regional Report

Watch for Black Widow Spiders


Black widow spiders are most obvious and active during hot summer nights. The females have shiny black bodies with a red mark on their bellies that resemble an hourglass. They seldom bother humans unless threatened. If you leave them alone they'll help you by eating cockroaches and crickets.

Citrus Fruit Splitting

Insufficient water early in the growing season is the cause of citrus fruit splitting in hot weather now. Lack of water inhibits the rind\'s expansion as the fruit grows larger. There\'s nothing to do at this point but remove split fruit. Keep mature citrus trees watered to a depth of 3 feet and out to the edge of their canopy throughout the year.

Deadhead Flowers


Deadhead annual warm season flowers such as zinnia, sunflower, and cosmos to prolong their blooming period. Deadheading keeps the plant sending its energy to flower, not seed production. Cut flowers for bouquets and snip off dead flowers and toss them into the compost pile.

Water Effectively

Watch plants carefully during this stressful summertime heat. Signs of water stress include yellowing and wrinkling of leaves or wilting. Apply water slowly and deeply. Don\'t sprinkle plants with a hose. Sprinkling does little good and may harm plants. Water should penetrate 1 foot deep for annual flowers and vegetables, 2 feet deep for shrubs, and 3 feet deep for trees.

Wash Dusty Plants

During the summer monsoon\'s blowing winds, plants easily accumulate a layer of dust on their leaves. Spider mites love dusty conditions and use the opportunity to move in with roses being a favorite target. Wash dusty plants off with the hose early in the morning so plants can dry before the hot sun rises.

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