Water Containers Regularly
Keep container gardens well watered and fertilized. As the roots begin to fill up the container, water and nutrients are quickly depleted. Use a soluble plant fertilizer at half strength and apply when the potting mixture is slightly moist.
Prune Back Flowers
Now is a good time to cut back many annuals such as alyssum and lobelia to encourage more blooms for late summer and early fall. Cut back the plants by half and apply a granular, slow-release fertilizer. They will be in bloom again next month.
Watch for Tomato Pests
Be on the watch for disappearing leaves and stems on your tomato plants. It can happen overnight. The culprits are hornworms, large caterpillars with voracious appetites. Their green camouflage blends in with foliage and makes them difficult to spot. You can hand-pick the worms and drop them in a bucket of soapy water. Or use a biological control, Bacillus thuringiensis (Bt), which kills the caterpillars by infecting them with a fatal disease.
Prevent Spider Mite Invasions
Check landscape plants for spider mites, some of the most damaging hot weather pests. These sucking pests -- smaller than the head of a pin -- are found in colonies and they leave a fine webbing on the undersides of the leaves. Mites can be particularly bad in dark, dry places, such as the interior of evergreens. Spider mites will succumb quickly to a forceful spray of water and homemade soap sprays.
Give a Final Feeding to Perennials
Water the perennial and annual garden a day before you put down the summer's final application of granular fertilizer. Never fertilize a dry, stressed plant or it will suffer more stress. For some extra soil conditioning, add some compost at the base of plants after fertilizing.