Southern California Coastal & Inland Valleys
Keep Tomatoes Watered
Tomatoes and other large plants in loamy clay soil use about 1 inch of water in three days of hot dry weather. This means checking the soil frequently and watering when the top couple of inches are dry.
Water and fertilize melons deeply once a week for juicy, fleshy fruits. Hold off irrigating melons about a week before they will ripen so their sugars will concentrate.
Paint Tree Trunks
To prevent sunscald, especially on younger trees, paint the trunks with a coat of light-colored interior latex paint.
Cut Back Bloomers
Encourage repeat blooming by pinching or cutting back alyssum, coreopsis, crape myrtles, dahlias, delphiniums, dianthus, fuchsias, gaillardias, lobelia, marigolds, penstemons, petunias, rose of Sharon, salvias, and verbenas. Prune chrysanthemums and poinsettias for the last time to encourage them to bush out and keep the stems from becoming scraggly by autumn -- unless you prefer a droopy or curly-stemmed display.
Water and Fertilize Regularly
Continue watering and feeding the entire garden with a balanced fertilizer and manure tea or fish emulsion every other week or so for steady growth and food production. Foliar sprays of liquid seaweed help trees, vegetables, fruits, and ornamentals withstand heat stress. Pay special attention to shallow-rooted plants, which wilt and dry out quickly in hot, dry weather. Avoid overhead watering late in the day during warm weather, when leaves can't dry off by sunset, as this encourages diseases.