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 bandanna 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. Build raised beds and fill with topsoil and manure at a rate of one bag of manure to three bags of soil. Or you may edge new beds and begin amending soil. This should be done a few months before planting to give the amendments time to do their work, really to give the micro-organisms and earthworms a chance to do their jobs. A good perennial bed should be at least 25 percent organic matter. To make that happen, work a three-inch layer of compost into the first 12 inches of soil using a garden fork or a tiller if it is a large space. If your soil is heavy clay, also work in construction sand or expanded shale to break it up. (Not play sand as its grains are too small.) Mulch well to keep the weeds at bay until you are ready to plant come fall. (Follow the same instructions for new fall vegetable garden beds.)
- And while you are planning ahead, order your fall bulbs.
- 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. (This is why you should use landscape cloth only on paths or under structures. Earthworms can’t get to the goodies in the mulch through the cloth.)
- Deadhead, deadhead, deadhead. Many perennials will re-bloom if given a haircut after the first flush of blossoms passes, especially dianthus, tickseed, rudbekia 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 that will seek out subsurface moisture better. Shallow watering yields shallow roots in the soil zone that dries out the quickest, requiring you to water more. Deep watering once a week is always preferable to light watering every day or so.
- Prune roses lightly to encourage new fall growth, but don’t feed them or over-water. They are resting now.
- Pinch back dahlias and chrysanthemums to encourage bushier growth.
- New iris may be planted now and old ones may be divided now that their bloom is past. Remember iris do not like to be planted deeply. Barely cover the rhizomes with soil, then mulch lightly. Water them in and leave them alone.
- Daffodils and other bulbs may be dug now and dried to be divided and replanted in the fall.
- 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 their heads where you want them to come up next year.
- Plan new beds to be planted this fall. Build raised beds and fill with topsoil and manure at a rate of one bag of manure to three bags of soil. Or you may edge new beds and begin amending soil. This should be done a few months before planting to give the amendments time to do their work, really to give the micro-organisms and earthworms a chance to do their jobs. A good vegetable bed should be at least 25 percent organic matter. To make that happen, work a three-inch layer of compost into the first 12 inches of soil using a garden fork or a tiller if it is a large space. If your soil is heavy clay, also work in construction sand or expanded shale to break it up. (Not play sand as its grains are too small.) Mulch well to keep the weeds at bay until you are ready to plant come fall. Use a soil tester to see if you should add lime to acid soil. Most vegetables prefer neutral soil with a pH of 6.5 or 7. Add lime now if you need it, as it takes several weeks to work.
- 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.
- Speaking of soil-borne tomato diseases, pick off lower branches of tomato plants and any branches that are yellowing. Dispose of all foliage you remove; don’t compost it. Once diseases get in the soil, it is very difficult to get them out. 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. Don’t be afraid to prune tomatoes. You can break off any of the non-fruiting foliage except the top few branches and the plant will still set fruit just fine.
- 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 moister better. Shallow watering yields shallow roots in the soil zone that dries out the quickest, requiring you to water more. Deep watering once a week is always preferable to light watering every day or so. 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 and beans.
- Your abelia, buddleia, crape myrtle, gardenias, hydrangeas and St. Johnswort 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.
- As you wait for apples to ripen, pull off fruit where more than one is growing from the same twig. It will keep branches from breaking from the weight and will allow the remaining fruit to grow larger and more disease free.
- 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 Bermuda, 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.
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