Heat and humidity are the twin demons that mean gardening in July in the South is not for the faint of heart. Nonetheless, the twins also make it possible to grow an incredible number of different plants, ranging from citrus trees to live oaks, from camellias to coreopsis. Just be careful to stay out of the noonday sun and drink plenty of water when you are outdoors. Protect yourself from the varied insect life that comes with the territory, and spend some time in a shady spot admiring the work you did in cooler months.
• Tomatoes are tropical fruits, but they will drop blossoms and fail to set fruit when temperatures stay above 90 degrees F. for several days. They will come back as temperatures moderate. Refresh them during heat spells by using shade cloth and misting.
• Prune off much of the foliage on tomatoes to increase air circulation and encourage fruit to ripen. Keep tomatoes mulched heavily.
• Harvest ripe crops every day. Even one ripe cucumber or tomato left on the vine will slow its production dramatically.
• If you haven’t already done it, create new beds for fall planting, either directly in the garden or in raised beds.
• Start fall plants indoors. Collards, chard, turnip and mustard greens and lettuce will all breeze through the mild winter, even if there is a rare snap of really cold weather. Use seed-starting kits or make your own using a good quality potting soil or seed starting medium in peat pots.
• Succession plantings of beans and corn can go in the ground this month to replace spent early crops of beans or greens from the spring. If beans were growing in the space, till the plants into the soil and plant your next crop. If corn or potatoes were growing there, fertilize with a nitrogen-rich amendment, such as 12-10-10 or cottonseed meal.
• There’s plenty of time to plant seeds for more quick bloomers like zinnias and dwarf sunflowers, marigolds and nasturtiums.
• Fill in beds where earlier blooming perennials are spent. Petunias, zinnias and other quick bloomers can still be set out now
• Cut back annuals that have already bloomed to encourage new growth and more blooming.
• Plant late summer or fall blooming bulbs, such as spider lily or autumn daffodil. Day lilies may be planted now as well.
• Dig up, divide and replant iris and daffodils if they are crowded. Soak iris rhizomes in water to plump them up before potting them up to share or putting them back in the garden.
• In established beds, make sure your mulch is fluffy. Replenish if it’s getting threadbare.
• Deadhead, deadhead, deadhead. Many perennials will re-bloom if given a haircut after the first flush of blossoms passes, especially dianthus, tickseed, rudbekia (Black-eyed Susan) and other hot-weather bloomers.
• Most established perennials don’t need extra water unless there is a drought. But if everybody seems to wilt before noon, water at dusk. Always water deeply as it encourages deeper roots.
• Camellias need no annual pruning, as do some flowering shrubs. Do examine the camellias for pests and treat if necessary. Do not use an insecticidal oil when temps are above 80 degrees, as it will ‘fry’ the soft tissue of the leaves.
• Fall is the best time to plant trees, but now is a great time to plan where you would like to have some lovely shade trees.
• Some good shade trees to consider are live oaks, tupelo (or black gum), Southern magnolia, Ginko and Florida maple.
• Consider deeply mulching with pine straw now in the area where you want to plant the tree to soften and enrich the soil. It will be much easier to dig a nice big hole for that new tree if you do.
• Mulch around existing trees and shrubs to conserve moisture and control weeds.
• July is a good time to lay sod for St. Augustine grass, zoysia grass or Bermuda Grass, all good hot-weather turf grasses. Till the soil down at least three inches, better six, and rake it smooth. Lay the sod. Water deeply and repeat every few days. You can fertilize established Bermuda and St. Augustine lawns now, but leave zoysia alone.