Extension Educator, Horticulture
Every grandma garden had a coral bell or two lining the sidewalk. Each summer the tight mounds of leaves would erupt with slender stalks bejeweled with tiny flowers. However with gentle coaxing from plant breeders, grandma's coral bells have been cavorting with other coral bell species to bring us variety in leaf colors and sizes and to make a favorite perennial more adaptable.
Heucheras (pronounced WHO-ker-as) or coral bell species are native to New England up to western Canada and down into Mexico. We now know heucheras as plants with incredibly colorful foliage of vibrant purples, chartreuse, and silver variegation but grandma's choices were limited to green and greener.
According to University of Illinois Extension horticulture educator Greg Stack, the heuchera revolution started when new forms were introduced in the 1990s. Hybrids between the old standard 'Palace Purple' and 'Dale's Selection' provided the basis for the introduction of many strikingly beautiful cultivars that offered leaf color and variegation not seen in the original species.
Enter the shining star in heuchera breeding, Heuchera villosa. According to Stack, this heuchera is a southeastern U.S. native. Compared to common heuchera it is larger, with rounded leaves resembling maple foliage, later to bloom, tolerant of more heat and humidity, and does well in dappled shade to sun.
Older heucheras prefer shaded, cooler gardens. By combining some of villosa's outstanding traits with other heuchera, breeders have been able to give the gardening world colorful plants that hold up well to heat, humidity, and a wide range of soil conditions.
A few notable heucheras:
While the villosa hybrids bring a more vigorous, heat-tolerant, and sun-tolerant plant to the garden, they will need a bit more moisture to look their best if planted in sunnier locations, according to Stack.
Heucheras in general do best in soils that are well amended with organic matter and are well-drained with an emphasis on well-drained. Heucheras have a very fine fibrous root system that does not fare well in wet soils, especially during the winter. Wet winter soils also lend to frost heaving.
Alternate freezing and thawing cycles will literally push the plant out of the ground. To combat this, pick a well-drained site and in the fall put down a layer of compost around the plants.
In spring if frost heaving has occurred, add more compost around plants. Or reset them by digging the plant and replanting it a bit deeper to recover the roots.
In addition to offering color to the shady garden, heucheras compete very well with tree roots and will even grow under walnut trees. One more reason to add heucheras to your landscape design.