Tiarellas are clump-forming perennials that bear small white, sometimes pinkish, star-shaped flowers on erect stems. Tiarella grows best in full or partial shade in moist, but not wet soil.
Tiarella grows from rhizomes; rhizome spread can be vigorous. Plants from clumps of basal, ovate to heart-shaped or rounded leaves that are toothed. Foliage often turns reddish copper in autumn and winter but does not disappear.
Plant Tiarella in shady borders or rock gardens or near shade-covered ponds or streams.
Get to Know Tiarella
- Plant type: Perennials
- Growing zones and range: Zones 3 to 8
- Hardiness: Mostly evergreen
- Height and width: 6 to 10 inches (15-25cm) tall and wide
- Foliage: Toothed, basal, evergreen foliage may change color in autumn; leaves have prominent veins and are bristly; narrow, erect flower stems.
- Flowers: Airy panicles of small star-shaped white, sometimes pinkish flowers
- Bloom time: Spring to summer
- Uses: Shady border or rock gardens, ground cover
- Common name: Foamflower, sugar-scoop
- Botanical name: Tiarella
- Family name: Saxifragacceae
- Origin: North America
Where to Plant Tiarella
- Plant Tiarella in partial to full shade.
- Grow Tiarella in humus-rich, well-drained soil that is slightly acid.
- Tiarella grows naturally in damp woodlands and along stream banks, but constantly wet soil can kill Tiarella.
When to Plant Tiarella
- Plant division in spring or autumn.
- Start seed in a cold frame in spring and set plants in the garden in autumn or the following spring.
Planting and Spacing Tiarella
- Space Tiarella 12 inches (30 cm) apart.
- Sow seed 1/8 inch deep in evenly prepared soil or start seed indoors in light potting mix.
How to Water and Feed Tiarella
- Keep the soil evenly moist, but not constantly wet.
- Fertilize Tiarella with an all-purpose organic fertilizer in spring.
- Rhizome roots can be fast growing; divide roots or clumps and replant to keep plant vigorous.
Tiarella Pests and Diseases
- Tiarella is prone to rust and is susceptible to slugs.
- Propagate Tiarella by seed sown in spring.
- Propagate Tiarella by digging and dividing clumps in spring or fall.
- Dig up individual plantlets that emerge at the end of runners and replant them.
Tiarella Varieties to Grow
- Tiarella cordifolia, foamflower: Perennial forms 12-inch-wide (30cm) clumps of light green leaves that show red-and-yellow fall color; leaves are deeply cut and veined with maroon; spreads by stolons.
- T. trifoliata, sugar-scoop, western foamflower: Perennial with deeply cut dark green leaves; upright clusters of small white flowers on 16-inch (40cm) stalks.
- T. wherryi: Resembles T. cordifolia; flower clusters are sometimes pink-tinted; cultivar ‘Eco Red Heart’ has dark red centers and veins, ‘Oakleaf’ has deeply lobed leaves and pink flowers.