Plant Lovers’ Almanac: Made for shade

Looking for shade-loving, carefree native perennials that will add color to dark garden spaces?

Look no further than the tiarellas and heucheras, commonly known as foamflowers and coralbells. These North American natives are as much at home in the garden as they are in the rich, shady woods of Appalachia.

Thanks to many hybrid crosses, foamflowers and coralbells are available with interesting flowers as well as an assortment of leaf shapes and colors.

Tiarella

Let’s start with my favorites, the tiarellas. Once planted only by native plant enthusiasts, these cheerful perennials have now earned a place of their own in the shade garden. In their natural habitat, foamflowers grow in moist, well-drained soils in damp woodlands or along stream banks. They form spreading mounds of foliage, topped with foamy white flower spikes in spring.

The most commonly grown tiarella species is Tiarella cordifolia, also known as the Allegheny foamflower. Given a favorable site, this plant will spread through rhizomes to form clumps almost two feet wide. Mounds of heart-shaped leaves are topped by multiple spikes of creamy white flowers in spring. Wherry’s foamflower (Tiarella wherryi) is a compact perennial, spreading more slowly than T. cordifolia. The leaves are maple-like, and will add interest in the garden long after the spikes of foamy white flowers have faded.

Tiarellas are now widely available in myriad leaf shapes and shades, from heart-shaped to deeply lobed in shades of green and burgundy. With so many cultivars now available, it can be difficult to keep track, especially with the yearly addition of new introductions. One of my favorites is ‘Spring Symphony,’ a plant that blooms reliably with pink buds opening to light pink flower spikes, held over deeply lobed leaves with dark maroon veins. ‘Tiger Stripe’ is a vigorous selection with maple-shaped leaves and light pink flowers, while ‘Iron Butterfly’ has almost black leaf centers with white margins.

Heuchera

Heucheras, also known as coralbells, are grown for their colorful flower spikes or for interesting foliage, with some cultivars combining both features. Dozens upon dozens of hybrid coralbell cultivars are available in the trade, making for a confusing choice at the garden center. On the foliage side, the best-known heucheras are the dark bronze ‘Palace Purple’ and reddish-burgundy ‘Chocolate Ruffles.’ ‘Citronelle’ glows in the garden with chartreuse foliage. While leaf color may fade in the heat of summer, the rich hues will return with cooler fall temperatures. Some gardeners enjoy the sprays of white flowers produced in summer, while others remove them to keep emphasis on the leaves.

Coralbells grown for their flowers produce spikes of brightly colored flowers held over mounds of green foliage. Flowers are available in shades of red, pink, coral and white.

The best cultivars also produce interesting, scalloped leaves in hues of green, providing interest after the flowers have faded. Popular cultivars include ‘Firefly,’ with rich red flowers, ‘Raspberry Regal,’ blooming in raspberry red over marbled leaves, and ‘Rosmundi’ with pinkish-coral flowers. For white flowers, try the cultivar ‘June Bride.’

Coralbells can tolerate more sun than foamflowers, so they can be used both in the shade garden and in sunnier sites. They perform best when given afternoon shade, and may need to be watered in sunnier sites if soils become dry.

In dense shade, coralbells grown for their flowers will not bloom well, and leaf color on coralbells grown for interesting foliage may fade. Partial shade and moist, rich soil create the ideal conditions for these plants.

Heucherella

Somewhat uncommon in the plant world are hybrid crosses between parent plants in different genera. This is the case with foamybells, a plant resulting from a cross between the foamflowers and coralbells.

This cross brings the best traits of the parents to create offspring with interesting foliage and flowers. Foamybells are more delicate in appearance than the heucheras, and have pink or white flower spikes that are a mix between the fluffy rounded foamflowers and the taller, more colorful coralbells.

For impact in the garden, try the heucherella cultivar ‘Sun Spot.’ This plant’s golden leaves with burgundy veins and bright pink flowers are eye-catching in the late spring shade garden. Other stand-out heucherellas include ‘Bridget Bloom,’ with whitish pink flower spikes held over green leaves, and ‘Pink Frost,’ bearing bright pink flowers on two foot stalks surrounded by frosted leaves with green veins and margins.

Like their parents, heucherellas prefer partially shady sites with rich, moist but well-drained soils. Mature clumps can be divided in spring.

Denise Ellsworth directs the honeybee and native pollinator education program for the Ohio State University. If you have questions about caring for your garden, contact her at 330-263-3700 or click on the Ask Denise link on her blog at www.osugarden.com.