Grow your flowers in the summer heat
by Ellen Goff
Got a dry, sunny flower bed that's inhospitable toward your summer blooms? Me, too. After years of failure, I now know there's not enough water in any Southeastern state to quell the region's scorching summer sun.
My landscape disaster area is a case study for "right plant, right place." The problem is the Southeastern gardener, not the garden.
What was I thinking? Year after year, forcing water-hogging annuals and dainty-leaf perennials into this parched location and expecting different results was, by definition, crazy. I had to reconsider my plant choices and resist the urge to install plastic flowers. The blinding light of the obvious revealed a world of flowers that will grow — actually thrive and bloom — under hot sun and dry soil.
Plants that thrive in arid locations have adapted to the harsh environment. Deserts, rocky hillsides and dry prairies have high temperatures, wind, intense sunlight, low soil moisture and generally low humidity.
Hot dry bed planting tips
Consider height and form when developing your planting design:
LOW BORDER OR EDGING
Carpet Bugle — Ajuga reptans
Lamb's ear — Stachys byzantina
Stonecrop — Sedum
Thyme — Thymus
Verbena — Verbena
Black-eyed — Susan Rudbeckia
Butterfly weed — Ascelpeas turberosa
Daylily — Hemerocallis
Gaura Gaura — lindheimeri
Goldenrod — Solidago
Lavender — Lavandula
Tickseed — Coreopsis
Yarrow — Achillea
TALL, BACK BORDER
Beebalm — Monarda
Gayfeather — Liatris
Purple Coneflower — Echinacea purpurea
Rosemary — Rosmarinus
Russian sage — Perovskia atriplicifolia
Texas sage — Salvia
The plants' physical characteristics evolved in order to survive. Leaves that resist water loss are smaller, thick, often waxy-coated or have fuzzy hairs. Roots spread extensively over a wide area or form single tap roots that pierce deep into the soil to find scarce moisture. As a result, all heat-lovers demand is excellent drainage. Amend the Southeastern soil with light gravel and a small amount of compost.
Now you're ready to make selections from among these plant groups and habitat categories: succulent, herb, grass, prairie and native. They're considered drought-tolerant and low maintenance. But they all need to be watered regularly until they become established, which is six to eight weeks. A few inches of mulch will help retain soil moisture as the plants acclimate.
One climate peril that can do in these tough guys is our thick, sticky, Southern humidity. Fungus disease can consume an entire planting bed if left unchecked. Increase air circulation by providing generous space among plants. Maintaining a clean bed by regularly picking out dead and dying leaves, and pruning out the lowest branches of each plant to allow air to flow from beneath also helps control fungus disease.
Heat hardiness and growth performance varies from the Carolinas to Florida. Allan Armitage, an esteemed plant expert, realized the need to develop and evaluate perennials and annuals that could grow and thrive under our region's hot, humid conditions.
For more than a decade, Armitage has directed the University of Georgia Trial Gardens in Athens. His program produces collections of unique heat- and humidity-tolerant plant varieties that are raised and tested in several trial gardens around the south. You can see photos and review performance ratings of plants that have been tested in trial gardens by visiting ugatrial.hort.uga.edu.
Ellen Goff is a freelance horticulture writer and photographer. She's passionate about plants, water quality and protecting the environment. Aside from working with words and pictures, she stays busy with her home landscape and its inhabitants along the shores of Lake Wylie, S.C.