Plant container-grown perennials. Toss a shovelful of compost into perennial planting holes to enhance soil nutrition and improve moisture holding ability. Don't forget to water while plants settle into their new homes.
Choose perennials that will give a strong performance in late summer, when Southern gardens tend to fade. Great selections include salvias.
Autumn sage (Salvia greggii): Red blooms lure hummingbirds. Plants possess strong drought-tolerance.
Brazilian sage (Salvia guaranitica): Striking indigo blue blooms attract butterflies. Look for the cultivar 'Black and Blue', which has blue flowers with black bases. Try a heavy winter mulch in Zone 7 to enhance overwintering.
Mexican bush sage (Salvia leucantha): This beauty isn't hardy through the whole South, but its spectacular lavender fall color makes it worth growing.
Test Garden Tip: You can also water newly planted perennials with a specialized transplant fertilizer. These products typically contain Vitamin B-1, which activates plant disease resistance, and rooting hormones, which promote strong root growth.
Keep sowing seeds of lettuces and garden greens weekly to ensure a long harvest season.
Test Garden Tip: Sow seeds of heat-tolerant greens to extend the harvest window. Give greens afternoon shade for best growth. Top choices include 'Jericho' (romaine), 'Buttercrunch' (butterhead), 'Craquerelle du Midi' (romaine), 'Lolla Rossa' (looseleaf red), 'Black-Seeded Simpson' (looseleaf green), and oakleaf types. Malabar spinach also thrives in summer heat.
Continue direct sowing seeds of beans, squash, melons, and okra. If cutworms are a problem, put collars around seedlings using recycled household items: canned food tins with bottom lids removed or toil tissue tubes cut in half.
Seedlings of tomatoes, peppers, and eggplants should be in the garden now, in all but the northern fringes of the Southern region. Even in these parts, you can plant seedlings; just be prepared to provide frost protection if a cold snap threatens.
If needed, prune azaleas immediately after flowering. Make cuts to shape shrubs or remove any damaged branches. Add container or balled-and-burlapped azaleas to the landscape now.
Test Garden Tip: To avoid disappointment and know you're buying a particular color azalea, choose a plant that's in bloom. Use the same technique with crape myrtles.
Replace mulch around azaleas, camellias, and roses. If you suspected or battled diseases and insects with these crops last season, remove and replace mulch to eliminate any hibernating critters or spores. If disease and insects haven't been an issue, simply replenish the mulch.
Refresh mulch on planting beds. If you have pine trees, gather free mulch: pine straw. It looks great around shrubs and on flowerbeds.
It's Time for Tubers
Overwintered caladium tubers emerge this month in the warmest parts of the South. In areas where caladiums are annuals, tuck new or stored tubers into the ground. Plant 2-3 inches deep.
Add cannas to your garden for a striking foliage show. Look for the colorful cultivars 'Tropicanna', 'Pretoria', or 'Bengal Tiger'. These are all eye-catching underplanted with asparagus fern and/or sweet potato vine.
Check with a local garden center to discover the right time to plant frost-tender tubers in the cooler parts and higher elevations of the South.
Get heat-loving annuals (zinnia, marigold, cosmos, salvia) in the garden as soon as seedlings are for sale. In the northernmost sections of the South, delay planting until all danger of frost is past.
Test Garden Tip: As you plant annuals, remove flower buds to encourage seedlings to direct energy to root growth. Pinch out growing tips to promote bushiness.
Grass is growing in earnest now. Time mowings so you're removing only one-third of total blade growth. Follow this guide to mowing height.
Zoysia: 1/2 inch
Bermudagrass: 1/2 inch
Creeping bentgrass: 3/4inches
Centipede: 1 inch
Kentucky bluegrass: 2 inches
Fine fescue: 2 inches
Bahiagrass: 2 inches
St. Augustinegrass: 2 inches
Tall fescue: 2-1/2 inches
Sharpen your mower blade frequently. A sharp blade makes clean cuts, while a dull one tears grass blades. A torn blade provides an entry point for disease.
Test Garden Tip: Keep an extra, sharpened blade on hand to ensure that you always have a sharp blade available.