Gardening Articles: Flowers :: Perennials
Heucheras: Versatile, Colorful Natives
by Lynn Ocone
Heuchera brighten woodland gardens and perennial beds, and are useful container plants.
Native heucheras, also called alumroot or coral bells, have always been high on my list of favorite perennials. I know the ones grown for flowers well from my years in California. Then I moved East and discovered the numerous new hybrids grown primarily for their bold, showy foliage. Here's what I've recently learned about this increasingly popular genus.
There are approximately 50 species in the genus Heuchera. All are natives of North America and Mexico. Natural habitats range from rocky cliff faces on California's coastal islands, where you'll find H. maxima, to seeps of North Carolina's Great Smoky Mountains, home of H. americana. Few of the species are grown as ornamental perennials. But there are now many hybrids and selections of them.
Because Heuchera species come from different climates and habitats, there are many regional distinctions. In the West, coral-flowered H. sanguinea is native to Arizona, New Mexico and Mexico and is very successful and popular in gardens there. It won't tolerate the extreme heat and humidity in the Southeast, however. In that region, two of the best are H. villosa var. macrorhiza (pale green leaves and late-blooming tiny white flowers) and H. americana, the rock geranium (green mottled with white leaves and greenish white to purplish flowers).
Beyond guesswork and experimentation based on hybrid parents' native ranges, it's hard to know exactly where different heucheras will grow well. Most garden varieties have not been tested nationally. According to Horticulture Director Bart O'Brien at Rancho Santa Ana Botanic Garden, Claremont, California, "People are experimenting with heucheras now more than ever, seeing what's available and learning what grows best for them."
Heuchera Hot Zones
There are regions where several kinds of heuchera grow well and are widely appreciated. In Oregon and Colorado, for instance, both foliage types (Heuchera americana) hybrids and showy flowering types (H. sanguinea) hybrids flourish side by side.In other regions, either flowering or foliage types predominate.
In California gardens, showy flowering types are best known. Gardeners there are excited by new crosses between Heuchera sanguinea and California natives such as H. maxima and H. rubescens. These produce bright pink and red blossoms.
In the Pacific Northwest, the Midwest and much of the East, foliage varieties have taken gardeners by storm. "They are hot and trendy in this area," says Rick Darke, curator of plants at Longwood Gardens in Pennsylvania. He especially values their year-round beauty and uses them extensively as ground covers.