Prepare Compost Piles for Summer
If turning compost when the thermometer reads 100+ isn't your thing, prepare the pile to sit through the long hot summer. Organic matter needs oxygen and moisture to decompose fairly quickly. Turn with a pitchfork, which will incorporate oxygen. Sprinkle with water from the hose regularly as you turn, so that ingredients have the moisture of a wrung out sponge. Don't wait to water from the top down after forming a new pile or most of the material won't get moistened. When finished, cover the pile with a tarp to help hold in moisture a bit longer.
Care for Tomato Plants
Tomato pollen isn't viable much over 90°F, so fruit won't set. Continue to water plants so existing tomatoes will mature and ripen. If you want to keep tomato plants alive through the summer to bloom and fruit again in the fall, provide shade cloth to protect them from the hot afternoon sun and cover the root area with 3-4 inches of organic mulch.
Prune Old Garden Roses
Once-blooming old garden roses (heritage roses) can be pruned after their spring bloom ends. They bloom on one-year-old or older wood, so pruning now will create wood for next spring's flowering. Use sharp by-pass pruners, which work with a scissors action. Seal all pruning cuts with wood glue to prevent cane borers from entering.
Plant Colorful Annuals
Sow seeds for sun- and heat-loving annuals such as zinnia, marigold, tithonia, gaillardia, cosmos, portulaca, salvia, and globe amaranth. Keep soil moist until seeds germinate. As seedlings grow, place several inches of mulch on the soil to maintain moisture and to reduce weeds and soil temperatures.
Watch for Praying Mantids
These delightful predators may be out and about in the garden as temperatures warm. They have long, slender bodies and sit with enlarged legs held upright to grab unsuspecting passersby. Their spherical egg casings look like hard brown styrofoam, about the size of a quarter to a half-dollar. They are often attached to plant stems or walls, so don't inadvertently destroy them as these are beneficial predators (although they eat as many good guys as bad).