The turtlehead, with the pink turtlehead being the most common, is a native wildflower of North America and is hardy in Zones 3-8. The plant has pointed leaves that are about 6 inches long in a dark green color. It grows to be about 2-3-feet tall on sturdy stems that usually do not need staking. You should, however, cut it back by about half in mid-spring to encourage a bushier, more compact growth and to keep the plant from flopping. Plant in fertile, somewhat acidic soil. Planting your pink turtleheads between two pine trees, for instance, is an ideal way to give them the shade they prefer plus the acidity that comes courtesy of falling pine needles. Do not, however, plant your turtleheads under trees with low hanging limbs. They need some space between them and the tree limbs.
Turtleheads prefer moist conditions. They can even handle full sun if planted in boggy conditions. They can also prefer partial shade - especially in the South where the afternoon sun is much hotter, but the soil should be kept moist and never allowed to dry out. (While turtleheads tend to be relatively trouble-free, they can develop powdery mildew if the soil is not kept moist and is allowed to become too dry.) Turtleheads also prefer cooler climates; therefore, they should be provided with protection from the hot afternoon sun in hotter climates, as previously mentioned. They can easily be started from seeds planted in the early spring. They can also be propagated by division. They should be divided in the early spring in cold climates and the early fall in warmer climates.
Most varieties of turtleheads, including the pink, begin to bloom in the late summer, and the blooms last into the late fall. (Bloom time is anywhere from 3-6 weeks or longer, with 8 weeks actually being about the average.) The blooms can be found not only in pink but also in red or white. At the end of the season, simply cut back to the ground and mulch. New growth will begin to appear in the late spring.
Following are some cultivars in which you might be interested in including in your own garden:
Pink Turtlehead (Chelone lyonii): Grows to be 1-3 feet tall and has a more open appearance than other species.
Rose Turtlehead (C. obliqua): Good for regions with hot summers and can also survive cold winters. Grows to be 2-3 feet tall and has rose-colored blooms. You might also like to try another variety of C. obiqua called 'Alba,' which blooms a bit earlier (mid- to late-summer) and has pure white blooms.
White Turtlehead (C. glabra): Blooms are white to creamy and frequently have a red or pink tinge. Prefers cooler climates.
Hodgson, Larry. "Perennials for Every Purpose". Emmaus, PA: Rodale Organic Living Books, 2000.
Roth, Susan A. "New Complete Guide to Gardening". Des Moines, IA: Meredith Corporation, 1997.