Tiarella trifoliata, commonly called “foamflower,” is a lovely woodland perennial within the Western hemlock/Douglas-fir plant community of the Pacific Northwest. Besides having beautiful soft green leaves that are often divided into three leaflets, its sprays of delicate flowers — of the palest pink — bloom on leafy stems for an amazingly long time: From May to as late as September. Really!
How it grows
This charming plant can be found in damp, shady forests, and near streams. It has rhizomes but doesn’t spread like typical ground cover plants; in fact, you’re more likely to find it self sowing than spreading speedily underground. There are three varieties: Tiarella trifoliata var. trifoliata, the one you’re most likely to find for sale, is found mainly west of the Cascades as well as in southern Alaska and British Columbia, at low to middle elevations. Tiarella trifoliata var. unifoliata occurs on both sides of the Cascades, west to Montana, and in B.C. and northern California, typically at higher elevations; it has more deeply lobed leaves. Tiarella trifoliata var. laciniata, has a very small range—only a few counties in Washington and Oregon and parts of B.C.; its leaves are maplelike and shallowly lobed. The other North American foamflower is T. cordifolia, native to the eastern U.S.
Tiarella trifoliata var. trifoliata’s dainty bell-shaped flowers, very close up.
Wildlife value
Foamflower’s clusters of tiny blossoms provide pollen and nectar for native bees and syrphid (aka hover) flies. Seeds are eaten by ground-feeding birds such as sparrows. Foliage provides cover for very small creatures and protects the soil.
Try it at home
Maturing to barely a foot tall and wide, it’s best grown en masse in the shade (or partial shade) of conifers where the soil is well-drained but naturally rich (or has been amended with organic matter, like compost), as well as along shaded pathways or near ponds and streams. Plant this gem in the fall for best results. If it’s not grown in a moist area, keep it happy with supplemental water during dry periods and it will self sow, but only in the most polite way.
Grab a partner
Grow foam flower with associated species such as Douglas-fir, western hemlock, western redcedar, vine maple, serviceberry, oceanspray, thimbleberry, sword fern, salal, Cascade Oregon grape, inside-out flower, oxalis, and many others.
This is so helpful. Please sign me up to your blog. Do you have an Instagram account?
Hi Jennifer, if you scroll toward the bottom (left side) on a page on my website you can add your email address and then hit “subscribe.” I’m not on Instagram right now but will consider it. Thanks!
They also appear to be quite tolerant of winter wet. I watched one spend all winter completely submerged in a seasonal stream to no ill effect.
Thanks for your comment. They grow naturally along shaded streams but wasn’t sure they could handle full submersion.