What hardiness zones is Sinojackia suitable for?

Sinojackia spp. species are deciduous trees or large shrubs reaching 15-25 feet (4.5-7.5 m) tall with a spread of 10-15 feet (3-4.5 m) and an upright to spreading, single- or multi-stemmed habit. Native to China, the genus contains approximately seven species, with S. xylocarpa and S. rehderiana most commonly cultivated. They produce simple, ovate to elliptic, dark green leaves 2-4 inches (5-10 cm) long. Pendulous clusters of small, white, bell-shaped flowers 0.5-0.75 inch (1-2 cm) across with yellow stamens appear in May-June—resembling small Styrax spp. flowers, to which the genus is closely related (both Styracaceae). Growth rate is moderate. Hardy to zone 6. Rare in cultivation—most specimens in botanical gardens and arboreta. Small woody fruits 0.5-0.75 inch (1-2 cm) persist on branches.

Native Range

Sinojackia spp. species are native to China—in moist forests and along streams in Hubei, Hunan, Jiangxi, and Zhejiang provinces.

Suggested Uses

Planted as a small specimen tree or in woodland gardens. Small white bell flowers May-Jun. Related to Styrax. Persistent woody fruits. Rare in cultivation. Small tree 15-25 feet. Zone 6. Needs consistent moisture. Not suitable for dry sites, exposed locations, or where nursery availability is limited.

How to Identify

Distinguished from Styrax spp. by the smaller flowers, the persistent woody fruits, and the generally smaller tree size. Distinguished from Halesia spp. by the pendulous (versus axillary) flower clusters and the woody (versus winged) fruits. Chinese jacktree—small white bell flowers resembling Styrax, pendulous clusters, persistent woody fruits, rare.

Appearance

Size & Dimensions

Height15' - 25'

Width/Spread10' - 15'

Reaches mature size in approximately 15 years

Colors

Flower Colors

white

Foliage Colors

green

Fall Foliage Colors

yellow

Bloom Information

Bloom Period

~3 weeks

Spring

Pendulous clusters of small white bell-shaped flowers 0.5-0.75 inch (1-2 cm) with yellow stamens, May-June. Resembling Styrax spp. flowers. Small woody fruits 0.5-0.75 inch persist. Bloom duration 2-3 weeks.

Detailed Descriptions

Flower Description

White; small bell-shaped 0.5-0.75 inch; pendulous clusters; yellow stamens; May-Jun

Foliage Description

Dark green; simple ovate to elliptic 2-4 inches; deciduous

Growing Conditions

Sun Requirements

Full Sun Partial Shade

Requires 4-8 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

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

5-7 years

Care & Maintenance

Care Guide

Plant in partial shade to full sun in moist, humus-rich, well-drained, acidic to neutral soil (pH 5.0-7.0). Hardy to zone 6. Consistent moisture. Shelter from cold winds when young. Rare—limited availability.