Silktree (Albizia julibrissin)

How much light does a Silktree need?

Silktree prefers full sun, which means six or more hours of direct sunlight a day. Part shade is also listed as an acceptable exposure for the tree. The record names both conditions, with full sun marked as the preferred one. The same listing describes silktree as a deciduous tree or shrub.

• Light: Full sun and part shade (full sun preferred)^1,2

How often to water a Silktree

Silktree's water range runs from dry to medium. The tree tolerates drought conditions well. It shows a deeper green color and a more lush appearance when it is given adequate moisture. Its soil can be well drained, moist or occasionally dry. A medium water level sits at the upper end of its documented range. No watering schedule is documented for this page.

• Water: Dry to medium³

Best soil for a Silktree

Silktree is listed for well-drained soil. Its drainage range also includes moist soil and soil that is occasionally dry. The tolerated soil pH runs from 5 to 8, which spans acid to alkaline soil. Soil at pH 5 and soil at pH 8 both fall inside the tolerated range, as does everything between them. No cited source here names a soil texture or an amendment.

• Soil drainage: Well drained, moist and occasionally dry^2,4
• Soil pH: pH 5–8⁴

Hardiness and temperature

Silktree is rated for USDA hardiness zones 6a to 9b. That spans eight listed zone steps: 6a, 6b, 7a, 7b, 8a, 8b, 9a and 9b. No cited source records a minimum temperature for this tree. A humidity preference is not documented either. Gardeners in zone 5 or colder fall outside the listed range, as do those in zone 10 or warmer.

• Hardiness: Zones 6a–9b¹

Pruning a Silktree

The pruning listed for silktree is light shaping. The source generally advises pruning when plants are dormant after cold weather. Light pruning can be done at any time. Dormant pruning is the general recommendation, while light pruning is the exception that suits any time. Silktree is deciduous. Heavier cuts are not described in the cited material.

• Pruning: Light shaping⁵

How to plant a Silktree

Plant silktree in USDA zones 6a to 9b. Plan for a mature height of 20–40 ft (6.1–12.2 m). Leave room for a mature width of 20–50 ft (6.1–15.2 m). Its growth rate is listed as rapid. Give it full sun, with part shade as the alternative. In the lower 48 US states it is introduced.

• Hardiness: Zones 6a–9b¹

Winter care

Silktree is hardy in USDA zones 6a to 9b. It is a deciduous tree or shrub. No cited source records a minimum temperature or a frost-protection method. In zone 5 or colder, the tree sits outside its listed range. The pruning guidance applies here: prune when plants are dormant after cold, and light pruning can be done at any time.

• Hardiness: Zones 6a–9b¹

How to propagate a Silktree

Propagation for silktree is listed by seed. Silktree seeds are dormant because of a hard seed coat. The seeds must be scarified to germinate. Seed is the only propagation method recorded for this page. No cutting or division method is documented. Dormancy in the seeds is the reason the source gives for scarifying them.

• Propagation: Seed⁶

Common problems

Silktree is susceptible to mimosa webworm, mites, shot hole borer and cottony cushion scale. The NC State listing also names Armillaria fungus and root rot among its susceptibilities. The diseases listed are fusarium wilt, leaf spot and rust. The Cornell entry describes the Fusarium vascular wilt disease as widespread in the southern US.

• Common pests: mimosa webworm, mites, shot hole borer and cottony cushion scale¹
• Common diseases: fusarium wilt, leaf spot and rust⁴

Questions and answers

Is silktree toxic to dogs?

A cited source lists silktree as toxic to dogs and describes a neurotoxin that can be toxic when ingested. Toxicity to cats is not documented on this page. That is a gap in the record, not a statement either way.

How much sun does silktree need?

Silktree prefers full sun, meaning six or more hours of direct sunlight a day. Part shade is also listed as an acceptable exposure. Its water needs run from dry to medium.

Which zones can grow silktree?

Silktree is rated for USDA zones 6a to 9b, which covers 6a, 6b, 7a, 7b, 8a, 8b, 9a and 9b. In the lower 48 US states it has introduced status.