August marks a unique transition in USDA Hardiness Zone 7, shifting from intense summer heat to the start of the fall planting season. The average first frost date typically falls between late October and mid-November, making the remaining warm days a precious resource for garden planning. Successful August planting maximizes this window, allowing newly sown seeds to germinate quickly in the warm soil. This strategy balances the needs of quick-maturing crops with the longer establishment times required by winter-hardy vegetables, ensuring plants mature before the first hard freeze.
Fast-Track Vegetables for Early Fall Harvest
The initial weeks of August are the last chance to plant vegetables that mature in under 60 days, yielding a harvest before the main fall crops are ready. Radishes are the fastest option, often reaching harvestable size in 25 to 30 days, making them an ideal choice for small garden spaces. Consistent moisture and a slightly cooler spot will help prevent them from becoming woody or bolting in the remaining summer warmth.
Bush beans are another excellent fast-track crop with a typical maturity time of 50 to 60 days. Unlike their vining relatives, bush varieties do not require trellising and can be direct-sown in early August to produce a concentrated harvest by late September or early October. Selecting short-season varieties is important to ensure the pods are ready before sustained cold weather arrives.
Quick-growing greens like leaf lettuce and spinach should also be sown now for an early fall yield. Loose-leaf lettuce varieties can be harvested using the cut-and-come-again method in as little as 30 to 45 days. Spinach matures quickly in the warm soil of late summer and can become sweeter as the temperatures drop toward October.
Cool-Season Crops Requiring August Start Dates
Longer-maturing cool-season vegetables must be started in August to reach full development during the milder weather of October and November. The brassica family, including broccoli, cabbage, and cauliflower, requires a long growing period of 60 to 90 days from transplant to harvest. Gardeners in Zone 7 often transplant seedlings of these crops in mid-to-late August, rather than direct-sowing, to save several weeks of establishment time.
Root vegetables like carrots, beets, and turnips require a direct-sow start in August, as they do not transplant well. Carrots need 60 to 75 days to reach size, and planting them now ensures they develop sweetness as the soil temperature cools in the fall. Beets and turnips mature in 50 to 65 days and should be thinned promptly after germination to allow the roots to swell properly.
August is also the time to prepare the soil for a later planting of garlic. While cloves are typically planted in October or November, turning the soil and incorporating organic material now allows nutrients to begin breaking down. This preparation ensures a fertile bed is ready when ground temperatures drop low enough for the garlic to establish roots before winter dormancy.
Non-Edible Planting and Soil Preparation
August is the final window for establishing non-edible plants and improving garden soil health. Cool-season annual flowers, such as pansies and violas, can be planted now for a vibrant display that lasts through the fall and often overwinters in Zone 7. Starting these ornamentals in late summer allows them to establish a strong root system that can withstand cold snaps.
Soil management for the winter begins with sowing cover crops in August after summer crops have been removed. Planting a nitrogen-fixing legume like crimson clover or a soil-loosening crop like Daikon radish helps prevent erosion and adds organic matter. Crimson clover should be sown six to eight weeks before the first hard freeze to establish and fix nitrogen before winter dormancy.
Techniques for Successful August Germination
The primary challenge for August planting is the high soil temperature, which can inhibit the germination of many cool-season seeds. To combat this, a technique called succession planting should be employed, where small batches of seeds are sown every two weeks to hedge against a heat wave causing a complete crop failure. Sowing seeds slightly deeper than recommended can also help, as the soil remains cooler and more consistently moist a half-inch below the surface.
Consistent, even moisture is important during the initial establishment phase, but the method of watering must be adapted to the heat. Rather than a single heavy watering, frequent, shallow applications, sometimes twice a day, help cool the top layer of soil and prevent seeds from drying out. Using a 30% to 50% shade cloth or a thin layer of burlap over newly sown beds can significantly lower the soil temperature and protect delicate seedlings from intense afternoon sun.