Heuchera, also called alum root, is one of the many low, mounding herbaceous perennials that are popular primarily for their foliage. They come in a range of colors from silver frosted green to chartreuse to ruffled burgundy leaves. Flowers in the late spring and early summer are tiny bells on long stems in shades of white, cream, pink and are easily incorporated into bouquets of cut flowers.
A North American native, heuchera or coral bells as it's also known, is now available in hundreds of colors. The basic leaf shape is palmate and deeply lobed. Once a small woodland plant, it is now of the most versatile perennials in the home garden.
Several excellent plants include 'Ginger Ale', 'Amber Waves' and 'Key Lime Pie' which are yellow, orange-gold, and chartreuse respectively. 'Ebony and Ivory' is striking for its dark leaves and white flowers. Combined with hosta, ferns, or other North American natives, the heuchera is a beautiful, low maintenance plant in many garden settings.
Heuchera are equally stunning grouped in the garden or in containers where it makes a spectacular filler.
Heuchera are readily adapted to Zones 4-9 and are hardy to about -25°F.
There are some varieties do quite well in full sun so check individual plant requirements if you have a spot with plenty of sun. The purple leaf varieties take full sun as long as they get adequate water. Some varieties, especially the yellow and chartreuse plants, tend to prefer s sunny eastern exposure that allows leaves to develop deeper color, but permits the afternoon shade they prefer.
To force brighter, more spectacular leaf color, remove the flowers. Some gardeners like the flowers so this is a matter of gardener's preference. The flowers don't need to be removed after blooming though it does make the plant and bed tidier.
Heuchera is not a heavy feeder, though it benefits from being enriched annually with good compost. They like a neutral pH of 6 to 7.7 with a preference for the limey side of the scale. If your soil is on the acid side, amend the soil with ground limestone.
Space so they have adequate ventilation as some varieties are susceptible to powdery mildew. Other than that, they have few problems with insects or disease and are relatively trouble free. The Black Vine Weevil is found in the Mid-Atlantic states, but can be controlled by adding beneficial nematodes in areas where this is known to occur.
Heuchera like rich, well-drained soil and should be kept watered regularly but allowed to dry out between watering. Many are moderately drought tolerant. In containers, heuchera do quite well in regular potting soil and tolerate some benign neglect. You can't ignore them all summer, but if you miss watering a couple days they are less likely to punish you with their untimely demise than many other container plants.
Heuchera are easily started from seed by storing collected seed after the bloom is completed. In the late fall, place in damp vermiculite for about 6-8 weeks in the fridge. In March, you can begin planting the seed in damp seedling mix on a bright window sill. Transplant outdoors in mid-May or after danger of frost is past.
The problem is that many of the coolest heuchera are propagated using tissue culture so it's likely that simple seed propagation won't get you the plant you want. Instead you'll get something from one of the grandparents and most likely you'll be surprised and possibly disappointed
Some gardeners have had success with divisions. Divide by digging up the plant and cutting it in half in the early spring every few years to facilitate plant health.
It's equally possible to propagate through leaf cuttings by dipping the stem in rooting hormone and placing it in a tray of moist sand or vermiculite. It's best to do this in the early spring, then transplant outdoors when all danger of frost is past. (Though the mature plants are cold hardy, the youngsters require some protection.)
In any case, after about 3-4 years, heuchera do start looking kind of seedy and so benefit from dug up and replanted because they literally grow up and out of the ground.
Heucheras and Heucherellas: Coral Bells and Foamy Bells by Dan Heims and Grahame Ware. These are two of the major players in the development of heucheras so they know what they're talking about.
Heuchera, Tiarella and Heucherella: A Gardener's Guide by Charles and Martha Oliver.