Summer is here, early, it seems, and any cool-weather plants I had not already replaced with heat-tolerant ones are unhappy. My peas are dead, and the broccoli that had not produced a crop is going to bolt to seed and skip forming a lovely head of broccoli. However, the weather is perfect for lima beans and okra, so get to work planting your garden.
In the flower garden, I’ve already replaced my pansies and cool-season plants with my favorite heat tolerant annuals. I water these a few times to get them comfortable in their new home, and then I ignore them the rest of the summer. They don’t even need deadheading. For sun, I use annual vinca, also called Madagascar periwinkle (see photo). It comes in shades of pink, white, and purple, and tolerates heat and drought. Deer don’t bother it. Do not confuse this with the evergreen vine called vinca; annual vinca is a bedding plant.
I also use Gomphrena globosa or gnome flower along the edges of my beds. It is available in pink, purple, and white, and blooms all summer with no care, and the cheerful yellow melapodium grows from last frost to first frost with no attention. I also use the sun tolerant annual begonia in borders and containers. For shade, impatiens bloom all summer with no attention from me.
When I planned my perennial garden, I consulted Jim Wilson’s book Bulletproof Flowers for the South
and PJ Gartin’s book Some Like It Hot : Plants That Thrive in Hot and Humid Weather
. As the titles indicate, they list plants that don’t mind 97°F and 90% humidity. Some of the plants they endorse, and plants I use in my garden, include Achillea, or yarrow, a ferny-leaved 15-inch high plant with umbrella-shaped flowers. Coreopsis, which comes in shades of yellow and orange, smiles at the sun, and Butterfly bush blooms all summer and into the fall and attracts clouds of butterflies.
Sun-tolerant annual coleus provides interesting combinations of colors in its leaves, and coneflower, a native plant, provides long-lasting purple, pink, or white blooms. Daylilies are tough, as evidenced by their habit of continuing to grow and prosper in highway medians and in ditches where someone discarded them long ago. Most people that garden in the shade use hosta, and they combine nicely with impatiens and Japanese painted fern.
When I lived in Charleston, I loved the large Lantana bushes that grew around many homes. Unfortunately, lantana is not reliably cold hardy here, and the large bushes don’t usually develop, but the low-growing lantana will often survive the winter, loves the heat, and makes the bees and butterflies happy.
Scabiosa, also known as pincushion flower, comes in pink and purple and butterflies constantly cover it. It blooms in the very early spring and remains green throughout the winter. Deadheading it, or cutting off the dead blossoms, creates a flush of new blooms. In addition, I can’t forget my faithful salvias, veronicas, calaminthas, and catmints that continue blooming no matter how hot the weather.