Albizia julibrissin | ‘Nemunoki’, ‘Persian Silk Tree’, ‘Sleeping Tree’ | 25 seeds
Albizia julibrissin (syn. Acacia julibrissin, Acacia nemu, Albizia nemu, Albizzia julibrissin, Mimosa julibrissin) is a small deciduous tree of the Fabaceae family which is originally native to eastern and south-western Asia. This popular ornamental is known by a great number of informal names, including ‘Bastard Tamarind’, ‘Lenkoran Acacia’, ‘Mimosa’, ‘Nemu Tree’, ‘Nemunoki’, ‘Nemurinoki’, ‘Nenenoki’, ‘Night Sleeper’, ‘Persian Silk Tree’, ‘Pink Silk Tree’, ‘Pink Siris’, ‘Shabkhosb’, ‘Silk Tree’ and ‘Sleeping Tree’.
Growing to approximately sixteen metres tall, julibrissin‘s trunk and broadly crowning branches are covered with dark green to grey, vertically striped bark. Featherlike, bipinnate green leaves reach roughly forty-five centimetres long by twenty-five centimetres across. Interestingly (as with some other plants, such as – to varying degrees – Mimosa hostilis and Mimosa pudica), these leaves slowly fold down at night and when it rains. Sweet smelling, summer-blooming flowers – highly alluring to bees, butterflies and hummingbirds – can appear in a bewildering away of colours, dependent on variety, etc. (think white to cream to pink to red to yellow). It should also be noted that the seeds of this species are poisonous and its pollen may cause allergic reactions!
There are currently two accepted varieties of this species; Albizia julibrissin var. julibrissin (the type, described here) and Albizia julibrissin var. mollis (distinct for its densely hairy stems). There are also several recognised forms, including Albizia julibrissin f. rosea (‘Pink Silk Tree’), a smaller (up to seven metres tall), more cold tolerant and pink-flowered type which is native to parts of Northern China and Korea. (aka f. ‘E.H. Wilson’ and f. ‘Ernest Wilson’). Popular in cultivation, f. rosea has earned the British Royal Horticultural Society’s Award of Garden Merit. Other commonly encountered forms include the white-flowered f. alba and the attractive cultivars ‘Ishii Weeping’ (aka ‘Pendula’ – growing with a drooping habit) and ‘Summer Chocolate’ (producing pale pink flowers and red to dark bronze foliage).
Although in some places considered to be an invasive species, Albizia julibrissin is a popular ornamental tree which is often found in public gardens and private collections. Occurring naturally in arid to semi-arid plains, sandy valleys and uplands, its seeds can remain viable even after extended periods of drought.
Plant in USDA Hardiness Zones 6-10 in sun to partial shade in well-drained, acidic to highly acidic soil. Space young plants at least ten metres apart to allow them room to reach maturity.
All the seed sold by Arkham’s Botanical was freshly and ethically sourced this year