Irrigation is of the utmost importance this month. Plants utilize water rapidly during late summer, vegetables especially, and it is essential that you get the right amount to them. Water all plants deeply at least once a week, allowing the moisture to penetrate at least six inches into the soil; tomatoes and other deep-rooted vegetables require much heavier waterings. Vegetables in containers require even more frequent attention; apply water until it starts to pour out from the drainage holes, and never allow the soil to dry out completely.
Deep watering may be beneficial for most plants, shrubs and trees, but for some California natives used to a dry season it can be lethal. Keep California oaks as dry as possible to prevent oak root fungus. And it is an absolute must to keep the beautiful golden-flowered native Fremontia dry in the summer. For a garden with low water requirements, consider planting some of the elegant California natives. But wait until the first rains; that is the natural time for them to start their growth cycles.
Azaleas do best in acid soil. Because most of our water is alkaline by the end of summer, it's a good idea to use an acid-type fertilizer; many are available at nurseries. If the leaves of your azaleas look pale or chlorotic , it could be due to a lack of available iron. Alkalinity sometimes unites chemically with iron, making it unavailable to plants. Use chelated iron to return them to good color. By the end of August, spring buds are forming, so do any shaping before then.