The genus Tiarella is a charming, shade-loving foliage plant for the woodland garden. Tiarellas produce sprays of small, attractive flowers on top of a short mound of green foliage. In the last 15 years, an enormous number of new cultivars have been developed and made available to gardeners, so there has never been a better time to collect and grow these wonderful woodland perennials.
Tiarella are commonly known as foam flowers, because their masses of tiny, spidery flowers atop short stalks collectively look like foam on a stick. The genus is native to eastern North America and Asia . The east coast Tiarella cordifolia is further subdivided by some taxonomists into three varieties: Tiarella cordifolia var. austrina , Tiarella cordifolia var. collina , and Tiarella cordifolia var. cordifolia . The varieties are based on leaf size, shape, and the presence or absence of stolons.
Tiarella are closely allied with the genus Heuchera and can be hybridized with it to make the intergeneric hybrid x Heucherella. In the wild, tiarella are generally found in woodland or mountainous environments. Like heuchera, tiarella prefer dappled shade but prefers a moister habitat than its botanical cousin.
Tiarella is an herbaceous shade perennial that grows a clump of leaves from a central crown held at or just below the soil surface. Each node on the crown contains a bud that will eventually form a new leaf, an inflorescence, or a stolon that gives rise to an offset. Tiarella stolons can be quite long and allow the plant to spread throughout woodland gardens as a ground cover. The wild-type plants can either be clumpers or wide spreaders.
The primary ornamental feature of tiarella leaves is their color, which is usually green with an occasional prominent maroon or purple branched central vein.
Tiarella are better for deep shade than their cousin heuchera but prefer the dappled sunlight found in woodland gardens. In deep shade their foliage color may fade. In North Carolina, a site with 3-5 hours of dappled sunlight per day is perfect. Tiarella prefer the pH in soils to be close to neutral and in order to pair them with more acid lovers, we recommend a pH of 6.2 - 6.5 that will allow all plants to be grown equally well.
Tiarella are low maintenance plants and can remain undivided for years in the garden without losing vigor. If they become tattered looking due to weather extremes, they can be cut back for rejuvenation, but this is not necessary.
The astringent tiarella leaves are generally left alone by deer and rabbits, but remember that in the middle of the winter a ravenous deer or rapacious rabbit will eat anything, including tiarella. Tiarella are generally not affected by insect pests. Occasionally black vine weevils can infest the plant, boring into the crown and killing the tops. Black vine weevils are controlled by systemic insecticides but if untreated, they will eventually kill the plant. Gardeners may sometimes see mealy bugs or slugs but they are easily controlled with commercial products. Rarely, foliar nematodes will cause ugly discolored patches on the leaf. There is no control for nematodes...avoidance is the key. Buy plants only from nurseries that scout for and remove infected plants.
Tiarella grow quite well in shade garden containers. They like well drained potting mixes without a lot of fertilizer. Keep the pots well watered in the summer but do not over-water in the winter. The pots will need some protection from cold winter winds.
Tiarella Species, groups and Cultivar List
Tiarella 'Black Velvet' PP-12,348 Tiarella 'Black Velvet' has deeply lobed leaves that are green with black veins and bluish white flowers.
Tiarella 'Brandywine' Tiarella 'Brandywine' has glossy green leaves that turn bronze in winter and large sprays of creamy white flowers. The plant spreads slowly to form a nice 10" clump with time.
Tiarella 'Butterfly Wings' PP 13,629 This amazing new introduction from Primrose Path is the most unique foam flower that we have seen. The lacy, heavily dissected foliage is marked with a dramatic black central pattern, which looks more like a high-dollar hardy geranium than a tiarella. Each of these vigorous, 1' tall, clumping, foam flowers is topped with clusters of light pink flowers in April. This is a must-have plant for the woodland garden.
Tiarella cordifolia This lovely native woodlander forms rosettes of fuzzy green leaves, giving rise to numerous 12" spikes of small white flowers...absolutely awesome when used in a mass in the woods.
Tiarella cordifolia 'George Shenk Pink' . This is a light pink-flowered form of foam flower that is a delight in any woodland garden. The base is the same fuzzy, green, 1' tall clumper that we all know and love... only the flower color has been changed to protect...whomever.
Tiarella cordifolia 'Oconee Spreader' This vigorous groundcover selection of foam flower is one that we discovered in 2000 while botanizing in the Oconee region of Pickens Co. in upstate South Carolina. In the garden, the glossy, green leaf, 10" tall rosettes spread nicely, forming a large 8' wide patch in 5 years. In spring, the clumps are topped with bottlebrush-like spikes of white.
Tiarella 'Crow Feather' PP-12,335 This Terra Nova introduction boasts deeply lobed green foliage with purple markings in the middle. In winter the leaves take on shades of pink, red, purple and black. The clumps are topped with pink bottlebrush-like flowers in early spring.
Tiarella cordifolia 'Dunvegan' From Dunvegan Nursery comes this spectacular foam flower with dissected 5-7 lobed leaves...resembling the hand of an extraterrestrial! Tiarella 'Dunvegan' makes a nice compact clump to 1' tall x 1' wide with stalks of very pale pink flowers in early spring. A nice addition is that the new foliage is tinged purple...great in a mass planting!
Tiarella cordifolia 'Eco Eyed Glossy' This seedling from the garden of Don Jacobs is known for its glossy foliage, quite a change from most early foam flower selections. The 1' tall x 1' wide clumps have the typical white flowers just above the foliage during the spring...great in the woodland.
Tiarella cordifolia 'Eco Rambling Silhouette'.This is another wonderful seedling from the garden of Don Jacobs, with a very dark reddish purple center pattern on each deeply cut, glossy leaf. This 12" tall running foam flower is topped with a mass of white flowers in early spring...a great ground cover.
Tiarella cordifolia 'Eco Red Heart' This Don Jacobs selection is known for its brilliant burgundy patterning in the center of each leaf. As with most foam flowers, it forms a 1' tall x 1' wide clump, topped with fragrant white flowers just above the foliage during the spring. A mass planting is absolutely charming!
Tiarella cordifolia 'Eco Running Tapestry' This tiarella from the garden of Pennsylvania's Dot Plyler, has fuzzy green, nearly round leaves emblazoned with a fabulous large black pattern extending far out from the veins. This is a runner but soon forms a great groundcover in the woodland garden. The typical white, 1' tall bottlebrush-like flowers top the 6" tall mat in early spring.
Tiarella cordifolia 'Eco Splotched Velvet' This Don Jacobs selection of foam flower from northwest Georgia, is recognized by its velvety textured leaves, with a dark reddish purple pattern at the base of each leaf...fragrant pale pink flowers top the 1' tall clump in early spring.
Tiarella 'Elizabeth Oliver' An older cultivar but still very nice has lobed green leaves have purple markings in the center. Light pink fragrant flowers are showier than most cultivars. Spreads slowly to 12" wide.
Tiarella 'Filigree Lace' This delightful new selection comes from Charles Oliver at Primrose Path. Tiarella 'Filigree Lace' has deeply lobed foliage, cut almost to the center of the leaf. Each leaf has a distinctive dark purple pattern at the base. Each 1' tall clump spreads to almost 18", making a great mass planting for any woodland garden...typical white flowers just above the foliage in spring.
Tiarella 'Jeepers Creepers' PP 13,437 This new Terra Nova introduction upgrades the creeping forms of foam flower. Instead of forming a tight clump, Tiarella 'Jeepers Creepers' makes a nice weed-suppressing 8" tall groundcover to 2-3' width. The deeply lobed, fuzzy, green leaves are each highlighted by a dramatic wide black vein pattern. In late spring, the mats are topped with white bottlebrush-like flowers. Tiarella 'Jeepers Creepers' is perfect as a backdrop for trilliums and other woodland bulbs.
Tiarella 'Laird of Skye' This new selection from Dunvegan Nursery has three lobed leaves with a nice ruffled edge. The nice white flowers are much larger than the typical species and rise 10" above the foliage...visitors will truly gawk over a nice 6" tall patch of this foam flower.
Tiarella 'Mystic Mist' PPAF This exciting Terra Nova introduction makes a 5" tall by 1' wide clump of white frosted, maple-shaped leaves, each highlighted with wide, dark-purple central veins. The clumps are topped with short bottlebrush spikes of white flowers in early spring. We are very impressed with the improved vigor over earlier variegated foam flowers.
Tiarella 'Neon Lights' PP 13,289 This Terra Nova hybrid has one of the most distinctive leaf patterns that we have seen. The deeply cut fuzzy green foliage is highlighted by a magnificent black-purple pattern that mimics the leaf form. In mid-spring, the 22" wide clumps are topped with 16" flower spikes of white...stunning even when not in flower!
Tiarella 'Pink Skyrocket' PP 13,382 PVR This 2002 release from the Terra Nova breeding program is the best pink-flowered foam flower we have seen. The 8" tall x 1' wide clump of strongly dissected, shiny green foliage, highlighted with a central black blotch, is topped in late spring with a dazzling display of 1' tall pink "brushes."
Tiarella 'Pirate's Patch' PP 14,907 Each fuzzy green leaf is highlighted by a dark central pattern of black. Each 5" tall by 1' wide clump is topped in late spring with a stunning display of 10" tall white bottlebrush-like flowers...hovering just above the foliage like a Texas buzzard over road kill. The breeders at Terra Nova have counted 250 flower spikes on a 3 year old plant...pretty dazzling! The winter foliage is a nice shade of bronze.
Tiarella polyphylla 'Heronswood Mist' This foam flower was discovered as a seedling from a Dan Hinkley collecting trip to Yunnan, China. Instead of having the normal green foliage, each fuzzy leaf is heavily dusted with a cream frosting...like a green leaf decorated with one of Martha Stewart's famed faux patinas. As the nights cool, the foliage takes on a pink overtone which adds to the uniqueness. In spring, each 8" tall x 1' wide clump is topped with the typical bottlebrush-looking white flowers.
Tiarella polyphylla 'Moorgrun' This foam flower from Asia resembles our native, with the same grape-shaped fuzzy green leaves. Instead of forming a clump, it spreads into a wonderful, fuzzy green 10" tall groundcover...if you've got the itch, roll around in this one for a while. The mat is topped with short, white, bottlebrush-like spikes in early spring.
Tiarella cordifolia 'Slickrock' This introduction was found by Jim Plyler near Slickrock Creek in North Carolina. The small maple-like leaves are about half the size of other tiarella. In addition, Tiarella 'Slickrock' spreads much faster than any other tiarella we have grown...a truly social shade perennial. In the spring, the 6" spires of light pink adorn this 6" tall woodland mat...very special!
Tiarella 'Spring Symphony' PP 12,397 This Terra Nova introduction may well be the best clumping tiarella that we have grown. The jagged, fuzzy green leaves are each highlighted by a black central blotch. In April the compact 1' tall clumps are topped with 1' tall, light pink, bottlebrush-like flowers... darker toward the tips. A mass of Tiarella 'Spring Symphony' is stunning in the woodland garden.
Conclusion
Tiarella are alluring hardy perennial plants for any garden. Their exotic foliage will fascinate you and their dainty flowers will delight you. Plant them in your garden and soon you'll be foaming at the mouth for foam flowers.
