|1||15C+||Indoor||Grow as a houseplant or under heated glass.|
|2||10 to 15C+||Indoor / Outdoor||Grow indoors, or outdoors in summer in a sheltered spot|
|3||5 to 10C||Tender||Grow outdoors in summer, and in a heated glasshouse in winter.|
|4||1 to 5C||Tender||Grow outdoors or under glass without risk of frost.|
|5||-5 to 1C||Half-Hardy||Hardy in coastal/mild/sheltered areas. Will not tolerate hard/sudden frost. May require winter protection in situ. such as fleece or straw mulch.|
|6||-10 to -5C||Hardy||May suffer at altitude, central/northerly locations, harsh winters, cold gardens and when grown in pots.|
|7||-15 to -10C+||Hardy||Will survive most severe winters but may be at risk in central/northerly locations and in pots. Top growth may be destroyed but will usually re-grow.|
|8||-20 to -15C||Hardy||Will survive severe winter, but may need protection when grown in pots.|
|9||-20C & Colder||Very Hardy / Hardy||in the severest European climates.|
Originating from Iran, China, Korea
A tree of such outstanding exotic character, tropical and lush with a flamboyant display of both foliage and flower that it seems impossible that it would be hardy in the UK, but is in fact perfectly happy growing unprotected in most of the country.
This form of the ‘Silk Tree’ has down-swept branches, making cascades of feather-shaped deciduous leaves, with their many tiny leaflets. They are finely detailed and complex and give the tree a soft texture that is as deserving of its common name as its flowers, which also have a dainty and slender form, made up of clusters of thread-like stamens resembling silk threads. They are often followed by flattened green seed pods that mellow to a soft tan colour, adding further late-season interest.
Although late into leaf, the many unique qualities of this tree make it a deserving addition to any garden; the character of its leaves and flowers are equalled by its overall form which makes it suitable for tight spaces, on patios or near paths. Its upright shape gives the ‘Silk Tree’ an architectural quality that gives it the presence to hold centre stage in a planting, as an accent plant, or in a pair framing a path or vista.
In its native Persian habitat it is known as the ‘Silk Flower Tree’. The species’ Latin name julibrissin is loosely based on this Arabic descriptive common name. The Japanese common name for Albizia is Nenenoki ‘The Sleeping Tree’ due to the many small leaflets closing up in the evening, like the ‘sensitive plant’ which closes its leaves when touched.
A drought-tolerant species when established, tolerant of coastal climates and poor soil. It will grow happily in an exposed position in full sun but for optimum vigour, it should be planted in a heat trap such as a courtyard or against a wall to achieve maximum leaf growth and flowering.
Height and spread after 3 – 4 years 1.5m x 80cm
Semi-mature height and spread after 6 – 8 years 2.5m x 1.2m
Potential mature height and spread after 20 years 6m x 2.5m