Chinese Flame Tree (Koelreuteria bipinnata)

Plant Snapshot

Common Name: Chinese Flame Tree
Latin Name: Koelreuteria bipinnata
Hardiness Zones: USDA zones 6–9. Less cold hardy in zone 6 and below may suffer dieback while zones 8–9 give best growth and flowering.
Typical Height: 15–35 ft (4.5–11 m) at maturity.
Typical Spread: 15–25 ft (4.5–7.5 m) crown spread.
Bloom Period: Summer blooming with yellow flowers. Exact months vary by region.
Soil Preferences: Prefers well drained soil. Tolerates poor and dry soils and neutral to slightly alkaline pH. Poor drainage can cause decline.
Light Preferences: Full sun to light shade. Best flowering and fall color in full sun.
Toxicity: No widely reported severe toxicity but avoid ingestion of seeds and consult poison control for exposures. Verify with authoritative toxicology sources for pets and children.
Propagation: Easily grown from seed. Can naturalize by self seeding. Softwood cuttings and nursery propagation also used.

Key Facts

Deciduous ornamental tree valued for summer yellow flowers.
Produces papery, lantern like seed pods in late summer to fall.
Native to parts of China.
Tolerant of a range of soils if well drained.
Performs best in full sun for best flowering and fall color.
Can self seed and naturalize in favorable climates.
Used in streetscapes and mixed borders for multi season interest.

Chinese Flame Tree (Koelreuteria bipinnata) is a small to medium deciduous ornamental valued for upright form, summer yellow flower panicles and showy papery seed pods. It fits streetscapes and mixed borders where a sunny specimen with multi season interest is wanted, but it can self seed under favorable conditions.

Identification

Look for a small to medium deciduous tree that commonly reaches 15 to 35 feet tall with a broadly rounded crown about as wide as tall. Leaves are pinnate and the tree produces conspicuous yellow panicles in summer followed by inflated, lantern like papery seed pods in late summer into fall.

Where to grow and best uses

Plant Chinese Flame Tree in full sun for best flowering and fall color, though it tolerates light shade. It adapts to a wide range of soils provided drainage is good and is often used in streetscapes, avenues and mixed borders for multi season interest. USDA hardiness is roughly zones 6 to 9 so check local conditions.

Planting and spacing

Space trees to allow a mature crown of 15 to 25 feet, typically planting 15 to 30 feet apart depending on site. Plant at the same root collar depth as in the nursery container and place in a sunny, well drained location. Timing for planting varies with climate; avoid installing in waterlogged sites.

Soil and watering

Chinese Flame Tree prefers well drained soil and tolerates poor and dry soils and neutral to slightly alkaline pH. Poor drainage and waterlogged conditions lead to root problems and decline, while established trees tolerate some drought. Water newly planted trees regularly until established and reduce supplemental irrigation once roots are established.

Flowering and seed pods

Showy yellow flower panicles appear in summer, with timing varying by climate. After flowering the tree produces papery, lantern like seed pods that persist into fall and provide winter interest. Pods also contain seed and can allow the tree to self seed in favorable sites.

After flowering care and managing spread

Remove unwanted seedlings and cut seed heads if self seeding is a concern, since plants can naturalize in favorable climates. Prune only as needed for structure and to remove dead or crossing branches. Avoid planting where natural areas could be colonized without checking local invasive species lists.

Propagation

Propagation is commonly by seed and the species is easily grown from self sown seedlings. Nursery propagation and softwood cuttings are also used. Expect seedlings to appear beneath mature trees and remove or transplant them depending on where you want more specimens.

Frequently asked questions

How fast does Chinese Flame Tree grow?: Growth rate is moderate and depends on site fertility, water and climate; trees commonly reach 15 to 35 feet tall at maturity under good conditions.
What USDA zones will it grow in?: Chinese Flame Tree is generally grown in USDA zones 6 to 9, with best growth and flowering in the warmer part of that range and increased dieback risk in colder winters.
Will it self seed and become weedy?: Yes. The tree produces papery seed pods and can self seed and naturalize in favorable climates. Remove seed pods or seedlings if spread is a concern and consult local invasive lists.
How should I water a newly planted tree?: Keep newly planted trees evenly moist until established to encourage root spread, then reduce supplemental watering. Avoid standing water because poor drainage causes decline.
When should I prune Chinese Flame Tree?: Perform light structural pruning to shape and remove dead wood as needed. Limit heavy pruning to maintain form and avoid excessive removal of flowering wood.