These days it seems that everyone is searching for a quick fix -- plants that perform from the minute they are in the ground until the first killing frost. If you are in that group, you'll welcome Purple Knight and Brazilian Red Hot, both varieties of alternanthera.
Botanically, they are both Alternanthera dentata. If you are not familiar with that name, consider them to be like Joseph's coats on steroids. The name Brazilian Red Hot indeed gives the clue that they are native to South America and Mexico.
These plants will be riveting in your garden because of their eye-catching foliage. Purple Knight leaves are such a deep, dark purple that they would almost pass for black. You'll be able to combine just about any other color of flower or foliage and have them dazzle. One striking partnership is Purple Knight and Torch Red Ember gaillardia, which is fiery red and yellow.
Brazilian Red Hot leaves are smaller than those of Purple Knight, but the iridescent shades of red-hot pink and magenta make this plant look like it is on fire. And the August sun and heat only make it ever more sizzling. I've seen great combinations with yellow lantanas, and a gaudy but dashing partnership with Blue Wave petunias. Almost any color will work with this plant, except for orange. Look also for a selection called Summer Flame with the same intense colors.
The Red Hot and Purple Knight will easily reach 24 to 36 inches, which makes them great backdrops for your other flowers. Space your plants about 18 to 24 inches apart, and they will quickly fill in. They fit in any style of garden, from the cottage look to tropical plantings. Try them in front of large bananas or upright elephant ears.
Like the small Joseph's coats you may be most familiar with, they do need fertile, well-drained soil. They can take anything summer can dish out, but they do not want to sit in soggy soil. They can still perform with a little midafternoon shade, but in the full sun, they reach their true potential.
These are very low-maintenance plants. Feed them with light applications of a slow-release fertilizer about three times during the summer and early fall. Though they are drought-tolerant, supplemental water during prolonged dry periods will keep them looking their best. If at any time you don't like their size or shape, cut back. New growth will quickly begin.
Horticulturist Norman Winter is vice president for college advancement, Brewton Parker College, Mount Vernon, Ga., and author of Tough-as-Nail Flowers for the South.