Celastrus orbiculatus (Asian bittersweet)

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Celastrus spp.

bittersweets

Celastraceae

Asia, Australasia, the Pacific, and the Americas

Attracts Pollinators Drought Tolerant

Native to North America

SunFull Sun – Part Shade

WaterLow · drought-tolerant

HardinessZones 3–8

Overview

Celastrus spp. is a genus of about 30 woody, twining vines in the staff-vine family (Celastraceae), native to Asia, Australasia, the Pacific, and the Americas. The stems climb by spiraling around supports and can reach 30-60 ft (9-18 m) into trees, thickening with age to several inches across and capable of girdling the trunks they ascend. Leaves are alternate, oval to rounded, 2-5 inches (5-13 cm) long, turning yellow in autumn before dropping. Small greenish flowers in early summer are easy to overlook, but the autumn fruit is conspicuous: rounded capsules split into three to reveal a yellow or orange shell around a fleshy scarlet-coated seed, held on the bare stems into winter. Most species are functionally one-sexed, so both male and female plants are needed for fruit. Oriental bittersweet (C. orbiculatus) spreads quickly by birds carrying the seed and by root suckers, smothering and girdling native trees, and it is regulated as invasive across much of the eastern United States. American bittersweet (C. scandens) is native there but is far less aggressive and is now scarcer where the Asian species has spread.

Native Range

Native across eastern and southern Asia, Australasia, the Pacific islands, Madagascar, and North and Central America, in woodland edges and thickets. C. orbiculatus from East Asia has naturalized widely in eastern North America, where it overlaps and hybridizes with the native C. scandens.

Suggested Uses

Native C. scandens is grown on fences, arbors, and posts for its yellow autumn leaves and long-lasting orange-and-scarlet fruit, and the cut stems are used in dried autumn arrangements. Both sexes are planted together so the female vines fruit. The invasive C. orbiculatus is managed and removed rather than planted across its naturalized range.

How to Identify

Recognized in autumn by clusters of rounded capsules that split into three yellow or orange valves, exposing a scarlet aril around each seed on otherwise bare twining stems. The alternate, finely toothed leaves turn clear yellow before falling. On the invasive C. orbiculatus the fruit sits in small clusters along the stem at the leaf joints, while native C. scandens carries its fruit in larger clusters only at the branch tips.

Appearance

Size & Dimensions

Height30' - 60'

Width/Spread6' - 15'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~3 weeks

Spring Summer

Small greenish to white flowers open in late spring and early summer (May-June) in branched clusters. They are wind- and insect-pollinated and are far less noticeable than the autumn fruit that follows. Because most plants are male or female, only female vines fruit, and only when a male grows nearby.

Detailed Descriptions

Foliage Description

Green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-12 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 - 7.5(Neutral)

357912

Soil Types

loam sand clay rocky

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

3-5 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Grow in full sun to part shade in almost any soil; the genus tolerates poor, dry, and disturbed ground and grows fastest in sun with steady moisture. Plants climb by twining, so a sturdy, long-lasting support is needed, as thick old stems can crush trellises and girdle small trees. Most species are hardy in USDA zones 3-8 and tolerate hard frost. Vigorous growth and bird-sown seed let plants escape cultivation, so spent fruit is removed before birds carry it where the genus is invasive. Cutting stems back hard controls size, though severed plants resprout strongly from the roots.

Pruning

Stems are cut back in late winter to control size and remove tangled or dead growth, and plants tolerate hard cutting because they resprout from the base and roots. Removing the fruit before it ripens limits bird-sown seedlings where the genus is invasive. Suckers around the base are dug out to keep a single plant from forming a thicket.