August Gardening Tips for the South
Summer sizzles in Southern gardens with colorful perennials and annuals.
Top Plants for August
Many plants paint Southern landscapes with colorful scenery this month. Watch these plants for an outstanding seasonal show:
Mexican bush sage (Salvia leucantha) Gray foliage topped with violet-and-white flower spikes make this drought-tolerant plant a standout. Plants grow to 3 feet.
Dahlia If you didn't at planting time, gently slip stakes into soil beside towering dahlias. To avoid spearing tubers, place the stake at least 6 inches away from the main stem.
Ornamental grasses Count on grasses to add graceful movement and late-season interest to landscapes. Many grasses also provide wildlife habitat.
Showy sedum (Sedum spectabile) This group of knee-high perennials continues its show this month. If you didn't pinch plants early in the growing season to encourage branching and sturdier stems, you might need to slip supports into soil to prevent flopping.
Garden mums (Chrysanthemum) Late in the month, mums will start appearing in garden centers. To enjoy the longest flower show, purchase plants with buds that are just beginning to open.
August Flower Garden Tips
Weekly deep watering -- from irrigation or rainfall -- is key for certain shrubs and trees, especially rhododendrons and azaleas, which are setting flower buds now for next year's blooms. The same is true for camellias. Plants that offer showy winter berries, such as hollies and firethorn, also appreciate consistent moisture now. If they get too dry, the immature berries may drop.
Roses Prepare everblooming roses for fall flowering by cutting plants back by about one-third. Also prune any dead stems. Feed plants using a rose fertilizer and renew mulch. Water roses deeply once a week if drought persists.
Impatiens Give leggy, lanky impatiens a haircut, trimming stems to half their length. After trimming, feed plants with a general water-soluble fertilizer, such as 20-20-20. You'll have bushy plants covered with blooms in time for autumn.
August Watering Tips
Sweltering summer days mean watering occupies much of a Southern gardener's time. Follow these tips to make the most of your irrigation efforts:
Time it right. The best time of day to water is early morning or early evening. Skip midday watering, because water will evaporate from soil quicker than it can soak in.
Don't worry about wilting. Many plants wilt under the intense heat of high noon -- even when soil is moist. Under the hot sun, plants lose water through their leaves more quickly than they can absorb it through their roots, which is why they wilt. Check plants in early evening. Leaves should be back to normal. If they're still wilted, water plants deeply.
Water the newbies. Plants added to the landscape this year or last fall are the ones that need water the most. When drought dictates watering restrictions, prioritize these newcomers over established plantings.
Wait before spraying. Plants that are drought stressed burn more easily when sprayed with pesticides. Water plants a few hours before you spray any chemicals.
Test Garden Tip: Reset irrigation timers monthly to ensure you're delivering the right amount of water at the right time of day. Install an automatic rain shutoff to eliminate unnecessary irrigation.
Harvesting Vegetables -- If you're lucky, you'll have lots to harvest this month. However, high temperatures can cause some edibles to stop producing. Be patient, keep watering, and wait for cooler temperatures when production most likely will resume.
- Continue to mow regularly, your best defense against weeds.
In the northern reaches of the South, plant fall vegetable crops. Sow seeds of greens, like lettuce, spinach, mustard, and turnips, along with beets and English peas. Look for transplants of collard greens, broccoli, and cauliflower.
In coastal areas and Florida, plant transplants of tomatoes, peppers, and eggplants. Sow seeds of summer squash, snap beans, and cucumbers.
Plant a fresh crop of heat-loving annual transplants to fill fall with colorful blooms. Choose cosmos, zinnia, marigold, celosia, or any other annual you find for sale.
Late summer is the time to sow wildflower seeds of bluebonnets, Indian paintbrush, Drummond phlox, coreopsis, and Gaillardia. Loosen and cultivate soil 1-2 inches deep. Scatter seeds, firm soil with a rake or by walking over it, and water. Keep the seedbed moist until germination occurs. Fall rains will help seedlings establish.
Lawns. Avoid mowing a dry lawn, which places grass under great stress. Wait to mow until after irrigation or rain. Arrange for your lawn to be mowed if you'll be gone more than two weeks on vacation. Otherwise, when you cut the grass, you'll remove more than one-third the blade length, which will stress turf.
Perennials. Divide spring-blooming perennials, including Oriental poppies, bearded iris, Brunnera, or veronica. If clumps are large, discard central portions that may be woody or dead.
Compost. Warm weather cooks compost fast. Empty your current batch and start building a new pile. The fresh compost is likely too hot to place around existing plantings. Dig it into new planting areas you plan to tackle next year, or simply set it aside to continue the composting process. Keep finished compost covered to prevent summer rains from leaching nutrients.
Houseplants. Continue to fertilize houseplants that are summering outdoors. For leafy plants, use a liquid fertilizer like 20-20-20 mixed to full strength. Apply every two weeks.
Bulbs. Plant fall-flowering bulbs as soon as you see bulbs for sale. For full sun, choose autumn-flowering crocus or Sternbergia. Tuck crocus into areas receiving light shade.