Coral Bells or Alum Root

(Saxifragaceae - Saxifrage Family)

Form

• small herbaceous semi-evergreen perennial
• basal foliage matures at about 1' tall by 1.5' wide, while the thin wispy inflorescences are up to 2.5' tall
• radiating clump growth habit

Culture

• full sun to full shade
• usually performs best in moist, rich, well-drained soils in partial shade; however, some of the purple-leaved forms will develop outstanding color and mottling in full sun to partial sun if given constant, even irrigation in Summer in well-drained, organically-enriched soils (otherwise, leaf scorch and plant dieback will occur)
• propagated primarily by crown division, but also by seeds or tissue culture
• Saxifrage Family, with few disease or pest problems
• abundantly available in containers, with a recent explosion of purple-leaved cultivars
• mulching helps prevent Winter frost heave of the shallow crowns that surface with age
• flowering period (especially for the green-foliaged forms) can sometimes be extended or rebloom encouraged by dead-heading
• optimally, division of plant crowns should occur once every three years, with the woody central portions discarded and the younger peripheral shoots replanted with their crowns well-covered in soil and mulch

Foliage

• simple, having three to five shallow lobes on the widely ovate leaves, about 3" wide and long, with crenate to dentate margins
• pubescent blades are borne on long petioles (mostly of basal crown origin)
• semi-evergreen foliage traditionally has been light green, dark green, or bronzed purplish-red, sometimes with a subtle silvery mottling
• recently, cultivars have been introduced whose foliage background color is green, bronze, plum, or purple, with patterns that are veined, marbled, mottled, or edged with dark purple, gray, or silver

Flowers

• white, pink, salmon, coral, or red
• bell-shaped miniature flowers are scattered on pedicels over the upper half of thin peduncles reaching up to 2.5' tall, well above the foliage, usually in June and sporadically thereafter

Fruits

• ornamentally insignificant (if not dead-headed)

Twigs

• not applicable

Trunk

• not applicable

ID Summary

• lush basal leaves, shallowly lobed and either green or purplish-silver in color and often prominently marbled along the veins, emerges on fairly long thin petioles and is the primary feature of this short perennial, although some cultivars have attractive, dainty flowers arranged along several tall inflorescences, creating a wispy flowering effect above the basal clump of foliage

USAGE

Function

• edgings, foundations, borders, beds, group plantings, naturalized areas, or as a non-traditional groundcover; marbled foliage variants are especially useful in areas with high shade or dappled shade

Texture

• medium texture
• thick density of basal foliage, but open density of the wispy flowering stalks

Assets

• attractive semi-evergreen foliage (many green, purple, bronzed, and marbled types exist)
• fine-textured small flowers on long peduncles

Liabilities

• frost heave and dieback may occur with age, due to surfacing crowns that are exposed in harsh Winters
• for the non-green foliage forms, leaf scorch and leaf bleaching may occur if placed in hot, dry, full sun areas

Habitat

• zones 3 (or 4) to 9, depending upon species, hybrid, or cultivar
• species are native to various regions of the United States, but most modern cultivars are of hybrid or tissue culture origin

SELECTIONS

Alternates

• perennials known for their interesting foliage (Athyrium, Cyclamen, Hosta, Pulmonaria, Polystichum, etc.)
• perennials with very fine-textured flowers (Astilbe, Convallaria majalis, Brunnera macrophylla, Polemonium caeruleum, etc.)

Variants

• many species, hybrids, and tissue-culture derived cultivars exist, selected primarily for foliage display or floral color
• Heuchera americana 'Dale's Strain' - green-blue foliage is heavily marbled in silver, sometimes planted densely and used as a groundcover
• Heuchera americana 'Garnet' - emerging foliage is bright garnet, changing to green with bronzed veins all summer, then reverting to an intense garnet center with a green margin all Winter, also planted densely and used as a groundcover
• Heuchera x brizoides 'Chatterbox' - rose-pink flowers bloom above the green foliage primarily in June, and sporadically throughout the Summer
• Heuchera micrantha 'Palace Purple' - the emerging deep crimson-purple foliage slowly bronzes throughout the summer, with relatively insignificant creamy flowers; best placed in full sun with adequate moisture for summer-long intense purplish color, as plants placed in shade will fade to a brownish bronze; the cultivar to which all others are compared, and 1991 Perennial Plant of the Year
• Heuchera sanguinea 'Frosty' - dark red flowers tower over the white- to frosty-green foliage
• Recently, a number of purple- or plum-foliaged forms for shady sites have been introduced that have veined or marbled "variegation" that can be either silver, gray, or dark purple; these are basically variations on the same theme and, while each is different, overall they look very similar at first glance, and herein are grouped together with a sampling of cultivars in alphabetical order: 'Cascade Dawn', 'Chocolate Veil', 'Persian Carpet', 'Pewter Veil', 'Plum Pudding', 'Purple Sails', 'Regal Robe', 'Ruby Veil', and 'Velvet Knight'.
• In addition, new purple-foliaged forms exist with ruffled, upturned edges that show the lighter intense lavender color of the leaf undersides; these tolerate a bit more sun, and include 'Can-Can', 'Chocolate Ruffles', 'Purple Petticoats', 'Ruby Ruffles', and 'Stormy Seas'.

NOTES

Translation

• Heuchera is named after the 18th century German botanist Johann Heinrich von Heucher.

Purpose

• Coral Bells is a perennial noted primarily for its basal foliage (especially the purple, bronzed, and/or marbled foliage forms), but also noted for its dainty blossoms on thin wispy flowering stalks (primarily on the green-foliaged forms).

Summary

• Heuchera is a showy foliage perennial with a radiating tight clump of green, purple, or marbled foliage, also having diminutive fine-textured flowers on thin stalks rising high above the foliage.