Primarily prized for their handsome foliage, heucheras or alumroots (Heuchera spp.) occupy a well-earned spot on my list of native perennials for shade. About 55 species belong to the genus, most from the western United states. Two are native to the Chesapeake Bay region: American alumroot (H. americana) and hairy alumroot (H. villosa). These two species, together with West Coast native crevice alumroot (H. micrantha), have been hybridized extensively to bring us a range of handsome plants suitable for shade gardens.
The Mount Cuba Center in Hockessin, Delaware, recently published the results of their three-year evaluation of heuchera hybrids. Since I only have one of their top-ten hybrids in my garden, I have some planting to do! Luckily, I visited the trial over the past few years and took photos of a couple of the top-ten plants. For a complete report on the trial, including a list of all ten top-scoring heucheras, see Mt. Cuba Center heuchera.
Above: Heuchera ‘Southern Comfort’ was among the top-rated heucheras and one of my favorites among the trial plants. In addition to the foliage color, I especially loved the size: Plants are about 14 inches tall and spread to about 3 feet.
Above: The Mount Cuba trial featured a row of each cultivar, so you could see how well each plant filled in over the course of the three years. This, again, is ‘Southern Comfort’.
Above: Another top-ranking cultivar, ‘Spellbound’, exhibits a bit of the color range featured in newer heuchera hybrids.
In my own garden, I use heucheras in shady beds in combination with hostas, epimediums, and native wildflowers. Most form 1- to 2-foot tall mounds of foliage that spread to 2 feet or more. The loose panicles of tiny flowers, borne in summer, are pretty but not spectacular.
Heucheras need rich, evenly moist, well-drained soil. They grow in full shade, but the leaves are more colorful in light to partial shade. A site with morning sun and afternoon shade is ideal, since it helps plants cope with heat. For this reason, in parts of my garden where I seldom water shade is a must. Fortunately, a simple soaker hose looped through the bed makes watering easy.
Above: Heuchera villosa ‘Autumn Bride’ is a favorite of mine. It is a large plant that is 14 or 15 inches tall, forming clumps that spread to 40 inches. It did not make Mt. Cuba’s top-ten list, but I am happy to report it did get an honorable mention. Here, it is growing under a Carolina allspice or common sweetshrub (Calycanthus floridus ‘Michael Lindsay’) and with variegated jumpseed (Persicaria virginiana ‘Painter’s Palette’.)
For best use as a ground cover, plan on massing plants, since the clumps get broader but are not rhizomatous. Most experts recommend dividing plants every 3 to 4 years—not something that I have managed to do with my plants. They are hardy in Zones 4 to 8.
Above: ‘Raspberry Chiffon’ finished in the middle of the pack in the trial, but it is one of several heucheras I have used successfully in mixed containers of perennials. Here it is growing with hosta ‘June’.