Xanthorhiza spp.

yellowroot

Ranunculaceae Eastern North America

Attracts Pollinators Deer Resistant

Native to North America

SunFull Sun – Part Shade – Full Shade

WaterMedium

HardinessZones 3–9

Overview

Xanthorhiza spp. is a monotypic genus in the buttercup family, represented by the single species X. simplicissima, the yellowroot, a low, suckering deciduous shrub of eastern North America. Plants grow 0.3-0.9 m (1-3 ft) tall and spread by underground stems into broad colonies along stream banks and on moist, shaded slopes. The bright yellow inner bark and roots, the source of the common name and of a traditional yellow dye, contain the alkaloid berberine. Leaves are pinnately compound with toothed, celery-like leaflets, clustered toward the stem tips, turning yellow, orange, and purple in autumn. In early spring, as the leaves expand, slender drooping branched clusters of tiny star-shaped flowers appear in shades of brownish maroon to purple. The plant grows naturally in the dappled shade of moist woodland, where it forms a low, even groundcover and tolerates damp soil and root competition. It spreads steadily once established but is not aggressive on dry sites. Roots and stems are bitter and contain alkaloids that can be poisonous if eaten in quantity. Frost-hardy across much of its range, it grows poorly in hot, dry, exposed conditions.

Native Range

X. simplicissima is native to the eastern United States, from New York and Pennsylvania south through the Appalachians to Florida and west to Texas. It grows along stream banks, in seeps, and on moist wooded slopes, often in shade. The plant frequently forms large clonal colonies in suitable damp ground.

Suggested Uses

Used as a deciduous groundcover for shaded, moist banks, stream sides, and woodland edges, and for erosion control on damp slopes. The autumn colour and even low habit suit naturalistic and native plantings. It fills shaded ground where lawns and many groundcovers fail.

How to Identify

Look for a low, colony-forming shrub under 1 m (3 ft) with upright unbranched stems topped by clustered, pinnately divided, toothed leaves. Cutting a stem or root reveals bright yellow tissue, a reliable field mark. Drooping sprays of tiny maroon to purple star-shaped flowers in early spring confirm the identification.

Appearance

Size & Dimensions

Height1' - 3'

Width/Spread2' - 5'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~3 weeks

Spring

Flowering occurs in early spring, roughly April to May, as the new leaves expand. Slender drooping clusters carry many tiny brownish-maroon to purple flowers that are easy to overlook. Small dry fruits follow in early summer.

Detailed Descriptions

Flower Description

brownish maroon to purple

Foliage Description

green, turning yellow-orange-purple in fall

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade SunFull Shade

Requires 2-6 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 - 7.0(Neutral)

357912

Soil Types

loam clay

Drainagemoist

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

3-4 years to fill in

Care & Maintenance

Care Guide

The shrub grows in partial to full shade in moist, humus-rich, acidic soil, and tolerates full sun where the ground stays reliably damp. Steady moisture matters most, as the plant comes from stream banks and seeps and grows poorly in dry, exposed sites. It spreads by suckers into a low colony, so room to spread or a defined edge keeps it in bounds. Frost-hardy through its range, it needs no winter protection. A mulch of leaf litter conserves moisture and feeds the shallow roots. Roots and stems contain bitter alkaloids and are poisonous if eaten, and few pests trouble the plant.

Pruning

Little pruning is needed. Stems that spread beyond the intended area are cut back or dug out with their suckers in spring. Old or damaged stems are removed at ground level to keep the colony low and even.