Boykinia spp.

Brookfoam

Saxifragaceae North America and eastern Asia

Attracts Pollinators

Native to North America

SunPart Shade – Full Shade

WaterHigh

HardinessZones 4–9

Overview

Boykinia spp. is a genus of about seven to nine rhizomatous perennial herbs in the saxifrage family (Saxifragaceae), native chiefly to North America with related species in eastern Asia. Most species grow along mountain streams, on wet rock ledges, and in moist shaded woodland. The plants form low clumps of long-stalked basal leaves that are rounded to kidney-shaped or palmately lobed, 1 to 6 inches (2.5 to 15 cm) wide, with toothed margins. From late spring into summer, erect flowering stems 8 to 40 inches (20 to 100 cm) tall carry open clusters of small five-petalled flowers, usually white and occasionally tinged pink, each 0.2 to 0.4 inch (5 to 10 mm) across. The fruit is a small two-beaked capsule releasing numerous small seeds. Boykinia spp. depends on cool, consistently moist, humus-rich soils and shade; in warm or dry positions the leaves scorch and the clumps decline. Species spread slowly by short rhizomes to form open colonies along watercourses.

Native Range

Boykinia spp. is native mainly to North America, concentrated in the mountains of the Pacific Northwest and California, with additional species in the Appalachian region and in eastern Asia. Plants grow along streams, seeps, and shaded slopes from foothills to subalpine elevations.

Suggested Uses

Grown in shaded bog gardens, along stream and pond margins, and in moist woodland borders. Lower species work as a groundcover in damp shade, while taller species suit the middle of a shaded, moist border. Spacing of 12 to 18 inches (30 to 45 cm) lets clumps knit into a colony.

How to Identify

Identify Boykinia spp. by its clumps of rounded to kidney-shaped, toothed and lobed basal leaves on long stalks, and its erect stems bearing branched clusters of small white five-petalled flowers. The flowers have a cup-shaped base, and the leaves often show coarse, sharp teeth. Its streamside habitat and clustered white flowers distinguish it from the rounder-leaved alumroots (Heuchera spp.).

Appearance

Size & Dimensions

Height8" - 3'4"

Width/Spread8" - 2'

Reaches mature size in approximately 2 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~4 weeks

Spring Summer

Flowering runs from late spring through summer, typically May to August depending on elevation and latitude, lasting about 4 weeks per clump. The small white to pink-tinged flowers open progressively up the branched stem. Cool, moist conditions extend the display.

Detailed Descriptions

Flower Description

white to pink-tinged

Foliage Description

green

Growing Conditions

Sun Requirements

SunPartial Shade SunFull Shade

Requires 2-5 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.0 - 6.5(Acidic)

357912

Soil Types

loam silt

Drainagemoist

Water & Climate

Water Needs

High

Frost Tolerance

hardy

Time to Maturity

2-3 years

Care & Maintenance

Care Guide

Boykinia spp. grows in part to full shade in cool, humus-rich soils kept consistently moist, with a slightly acidic pH of 5.0 to 6.5. Streamside and bog-garden positions, or any site with reliable moisture, suit it across the growing season. The foliage scorches in direct sun or when the soil dries, so shade and steady water are needed in warmer climates. A mulch of leaf litter conserves moisture and adds organic matter. Plants are otherwise low-maintenance and spread slowly by rhizomes.

Pruning

Spent flowering stems can be removed after bloom to keep the clump tidy; this is optional and does not affect plant health. Dying foliage is cut back in late autumn. Congested clumps are divided in spring to maintain vigour.