July is a tough gardening month in the southern zones. The heat becomes a character in the gardening saga that overwhelms all others. Often drought is the subplot. Remember that as you are out trying to keep your plants from roasting, you can be in danger of the same fate. Wear sunscreen and a broad-brimmed hat. A moist bandana around your neck can help keep you cool as well. Work in the morning or evening, rather than mid-day.
• Plan new beds to be planted this fall. Till ground and start adding amendments now, such as compost, course grit or expanded shale and cotton seed meal or blood meal. Dig in and mulch well. Keep weeded until you are ready to plant. By fall the amendments will be doing their work.
• Build raised beds and fill with topsoil and manure at a rate of one bag of manure to three bags of topsoil (not potting soil). Test the soil to see if lime should be added.
• And while you are planning ahead, order your fall bulbs and other perennials for fall planting.
• In established beds, make sure your mulch is fluffy. Replenish if it’s getting threadbare. Mulch holds in moisture and gives the earthworms organic matter to take down into the soil to nourish it.
• If your perennial beds are in need of renewal, rake back the mulch, put down a layer of compost and replace the mulch. The earthworms will do the rest of the work for you.
• Prune roses lightly to encourage new fall growth, but don’t feed them or overwater. They are resting now.
• Fill in beds where earlier blooming perennials are spent. Petunias, zinnias and other quick bloomers can still be set out now. Remember that as delicate as they appear, petunias can handle the intense heat and humidity better than almost any other flower. And their colors can’t be beat.
• When pulling up your early spring-planted annuals, such as poppies or larkspur, shake the seeds from their dried flowerheads where you want them to come up next year.
• Deadhead everything and cut back any plants that have gotten leggy to encourage another bloom.
• Now is the time to start seeds indoors for fall crops like broccoli, kale, collards, cabbage, onions and leeks. Almost all the brassicas (cabbage related plants) do better as fall crops in the southern zones and many will overwinter and give you greens to eat into the spring. You can set out the seedlings in late August or September.
• Outdoors, make sure you have a thick layer of mulch over any ground not thickly planted, especially around tomatoes. It will hold in moisture and keep a crust from forming on top of the soil that makes it hard for water to penetrate.
• Keep tomatoes staked or caged and thickly mulched to keep soil from splashing onto the leaves and spreading soil-borne diseases.
• Pick off lower branches of tomato plants and any branches that are yellowing. Dispose of all foliage you remove; don’t compost it. Make sure there is plenty of room for air to circulate around your tomato plants, as moisture held on the foliage is another vector for disease.
• Remember that very hot temperatures – extended days with higher than 90 degrees F – will cause tomatoes, peppers and eggplants to stop setting fruit. Don’t worry. When the temps go back down a bit, they will resume productivity. Make sure they have enough water during this time. Mulch also helps keep soil a bit cooler.
• Always water deeply as it encourages deeper roots that will seek out subsurface moisture better. Soak, don’t spray, and water at dusk or before 10 a.m. to keep from losing most of your moisture to evaporation. Water at the base of plants, rather than from above, if possible.
• Keep all your vegetables picked regularly. One over-ripe fruit will cause the plant to slow down production. This is especially true of okra, cucumbers, squash and beans.
• Your abelia, buddleia, crape myrtle, gardenias, hydrangeas and St. Johns wort are all blooming now. Wait until they are done to do any pruning other than cutting off spent blossoms. Cut off fresh blossoms to enjoy indoors and to encourage more blooming.
• If you must prune azaleas or camellias, do it now. They can also be fed now, but not later. You don’t want to encourage new growth too late that will be killed by frost.
• Water young trees in their first growing season and keep mulched out to the drip line at least.
• Raise your lawnmower blade to 2 inches or higher to allow the grass to conserve water and shade its own roots to cope with the heat.
• Hot-weather grasses like Burmuda, zoysia and centipede sod can be installed now. Loosen soil at least six inches deep before laying sod and make sure to keep it watered to moist but not soggy.