Physocarpus capitatus (Pacific ninebark)

1 / 5

Physocarpus spp.

ninebarks

Rosaceae North America and northeastern Asia

Attracts Pollinators Attracts Butterflies Deer Resistant Drought Tolerant Container Friendly

Native to North America

SunFull Sun – Part Shade

WaterMedium · drought-tolerant

HardinessZones 2–7

Overview

Physocarpus spp. is a genus of about 20 species of deciduous shrubs in the rose family Rosaceae, native to North America and northeastern Asia. Plants form rounded, arching shrubs 3-10 feet (0.9-3 m) tall and wide, with three-lobed, maple-like leaves 1-3 inches (2.5-7.5 cm) long. The common name ninebark refers to the mature bark, which peels away in thin papery layers to expose reddish-brown inner bark, a feature most visible in winter. In late spring and early summer the branches carry rounded clusters of small five-petaled flowers, white or flushed pink, each with a tuft of stamens, followed by clusters of small inflated red seed capsules. Foliage of the species is green, but many garden cultivars have been selected for purple, bronze, or golden leaves. Plants are hardy, wind-tolerant, and adaptable to a wide range of soils, tolerating both wet and dry sites and growing in USDA zones 2-7 in the hardiest species. The arching stems can become dense and twiggy with age, so the shrubs benefit from occasional renewal pruning. P. opulifolius of eastern North America is grown most often and is the parent of most colored-leaf forms.

Native Range

Physocarpus spp. is native to North America and northeastern Asia. P. opulifolius ranges across eastern and central North America, while other species occur in western North America and in China, Korea, and Japan.

Suggested Uses

Grown in shrub borders, informal hedges, and mixed plantings, with the colored-leaf cultivars used for foliage contrast. The hardy, adaptable nature suits cold-climate and low-maintenance gardens, including wet or clay sites. Ninebark also works in wildlife plantings, where the flowers draw insects and the dense stems shelter birds.

How to Identify

Look for an arching, rounded shrub with three-lobed, maple-like leaves and bark that peels in thin papery strips to reveal reddish inner layers. In early summer it carries rounded clusters of small white to pink flowers, each with prominent stamens, at the branch tips. The peeling bark, lobed leaves, and clustered inflated red capsules together identify ninebark.

Appearance

Size & Dimensions

Height3' - 10'

Width/Spread3' - 10'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~3 weeks

Spring Summer

Flowering occurs in late spring and early summer, roughly May to June, with rounded clusters of small white or pink-tinged flowers. The display lasts two to three weeks. Clusters of small red, inflated seed capsules follow and persist into autumn.

Detailed Descriptions

Flower Description

white to pink

Foliage Description

green (purple, bronze, or gold in cultivars)

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 6-10 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 Range5.5 - 7.5(Neutral)

357912

Soil Types

clay loam sand

Drainageaverage

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

3-5 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Ninebarks grow in full sun to part shade in almost any moderately fertile soil, tolerating clay, wet ground, and short droughts once established. Leaf color in the purple and gold cultivars is strongest in full sun and fades toward green in shade. The hardiest species withstand USDA zones 2-7. Plants need little feeding and are prone to powdery mildew in humid sites or where air movement is poor. Renewal pruning, removing a third of the oldest stems at the base each year, keeps the shrub open and vigorous. Self-sown seedlings appear occasionally but are easy to remove.

Pruning

Prune just after flowering, or in late winter where the seed capsules and bark are valued through winter. Remove up to one-third of the oldest stems at the base each year to renew the shrub and limit congestion. Hard cutting close to the ground is tolerated and produces vigorous new shoots with brighter leaf color.