Triadica spp.

Chinese tallow tree

HardinessZones 8–11

Overview

Triadica is a genus of about three deciduous trees in the spurge family, Euphorbiaceae, native to eastern Asia. The Chinese tallow tree, T. sebifera, is the widely known species, a fast-growing tree of 30-50 feet (9-15 m) with rounded to diamond-shaped leaves on slender stalks that flutter in the wind. In autumn the foliage turns red, orange, purple, and yellow before falling. Slim yellow-green flower spikes appear in late spring, followed by three-lobed capsules that split to reveal white, wax-coated seeds that persist into winter and give the common name popcorn tree. The waxy seed coat has long been processed for candles, soap, and oil in China. Like many spurges, the tree carries a milky sap, and its leaves, sap, and seeds are toxic if eaten and can irritate skin. T. sebifera has naturalised across the south-eastern United States, where it is listed as an invasive species and is banned from sale in several Gulf Coast states because it forms dense stands and displaces native vegetation. The genus tolerates wet and dry soil and grows quickly, which underlies both its garden use and its weediness.

Native Range

Native to eastern Asia, chiefly central and southern China, Taiwan, and Japan, in lowland woods, riverbanks, and disturbed ground.

Suggested Uses

In its native range and frost-free gardens it is grown as a shade and autumn-colour tree, and it was once planted for seed wax and oil. In the south-eastern United States planting is discouraged and restricted because of its invasive behaviour.

How to Identify

Recognised by rounded to rhombic leaves with a long-pointed tip on slender stalks that tremble like those of a poplar, turning vivid red and orange in autumn. Slender yellow-green flower spikes are followed by three-parted capsules that open to show three white, waxy seeds held through winter. The white popcorn-like seeds and milky sap separate Triadica from poplars and other look-alikes.

Appearance

Size & Dimensions

Height30' - 50'

Width/Spread25' - 40'

Colors

Flower Colors

yellow

green

Foliage Colors

green

Fall Foliage Colors

red

orange

purple

yellow

Bloom Information

Bloom Period

~3 weeks

Spring Summer

Yellow-green flower spikes open in late spring to early summer at the branch tips, with male and female flowers on the same spike. They are followed by capsules that ripen in autumn and split to expose white seeds. The seeds remain on bare branches well into winter.

Detailed Descriptions

Foliage Description

green, red and orange in autumn

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-12 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 - 8.0(Neutral)

357912

Soil Types

clay loam sand

Drainageaverage

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

5-10 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

The genus grows in full sun in a wide range of soils, from wet riverbanks to dry ground, across a pH of about 5.0 to 8.0. T. sebifera is hardy to roughly zone 8 and tolerates heat, flooding, and salt. Growth is rapid, and trees flower and seed at a young age. The milky sap is an irritant, and all parts are toxic if eaten. Because seedlings spring up densely from bird-spread seed, the tree has escaped cultivation across the Gulf Coast and is regulated as an invasive species there. Propagation is by seed or cuttings, though planting is restricted in many areas.

Pruning

Young trees are pruned in winter to a single leader and a clear trunk. Crossing and weak branches are thinned while dormant. Removing spent seed capsules limits the spread of seed where the tree is grown.