For bloom next spring, sow seeds of Canterbury bells, foxglove, hollyhocks, sweet William, and verbascum now in flats or small pots. Transplant seedlings to the garden in the fall when they're about 4 inches tall.
Flowering shrubs such as angel's trumpet (Brugmansia), hibiscus, plumeria, and princess flower are abundant in nurseries and ready to plant. So are vines like bougainvillea, passion flower, and thunbergia.
For instant color, tuck heat-loving celosia, marigolds, portulaca, Sanvitalia procumbens, vinca, or zinnias into garden beds. Or try angelonia; sometimes called summer snapdragon, it's now available in several colors. In shade, plant begonias, coleus, or impatiens.
Coreopsis, daylilies, gaura, kangaroo paws, lantana, lion's tail, rudbeckia, veronica, and zauschneria bloom well in heat. Shop for them now while they're plentiful in nurseries. But unless you live in a cool coastal location, wait until early fall to plant. Keep pots in light shade in the interim.
Coastal (Sunset climate zones 22-24) and inland (zones 18-21) gardeners can continue to plant summer vegetables. Set out cucumber, eggplant, pepper, squash, and tomato plants. Sow corn and snapbeans. Or plant year-round crops like beets, carrots, Swiss chard, and turnips.
Adjust mowing height. To keep their roots shaded and conserve soil moisture, allow tall fescues to grow to 3-4 inches during hot weather. Warm-season grasses like Bermuda and St. Augustine, on the other hand, should be kept at 1 inch or less to reduce thatch buildup.
To encourage further production, pick beans, chiles, cucumbers, peppers, and tomatoes frequently. Fast growers like squash should be checked almost daily.
Indoor plants look healthier and grow faster if they spend at least part of the summer outdoors. Give them a shady spot protected from strong winds. Spray the foliage with water occasionally to keep it clean.
After flower clusters fade, cut back stalks to two or three buds from the base of the plant.
When first bloom flush starts to fade, trim back dahlias; fertilize to encourage new growth.
Give shade trees a slow, deep soak monthly to ensure good health. Water established shrubs and perennials deeply too. Container plants may need daily soakings.
Birds usually peck at tomatoes and fruit because they're thirsty. Provide a birdbath or other water source, and you'll see less damage on nearby fruit.
Keep spider mites and thrips in check by spraying foliage often, particularly the underside of leaves. Clean foliage also encourages beneficial insects to move in ― they don't like dust.