Common Names: Persian Silk Tree, Pink Silk Tree, Pink Siris, Mimosa, Lenkoran Acacia, Bastard Tamarind
Scientific Name: Albizia julibrissin
Family: Fabaceae (the Legume, Bean, or Pea family)

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A well-known ornamental, the Persian Silk Tree has a lot more to offer than just beauty!

Description:
This small, legume tree is fast growing and short-lived. Known primarily as a tropical-looking, ornamental tree, it has many additional uses. It fixes-nitrogen into the soil which allows it to grow in poor soils and act as a pioneer plant in addition to fertilizing surrounding plants. While the leaves and flowers are edible, they are reportedly not great; however, many animals (wild and domesticated) use the leaves and pods/seeds for food, and they are increasingly used as a fodder crop. It attracts beneficial insects, bees, butterflies, and hummingbirds, and the wood can be used for many things, from furniture to firewood. The Persian Silk Tree (or Mimosa) is an ideal Permaculture tree to reclaim damaged soils and help establish a quality Forest Garden.

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Herbarium entry at the University of North Carolina.

History:
Native to southwester and eastern Asia (Iran, Korea, and Japan are known for cultivation), the Persian Silk Tree has spread around the world as an ornamental tree.

Trivia:

  • Genus name honors Filippo degi Albizzia who introduced the genus to Italy in 1749
  • Commonly called a “Mimosa”, the Persian Silk Tree is not closely related to the Mimosa genus
  • The Persian Silk Tree is used in traditional Chinese Medicine to “nourish the heart and calm the spirit”; recent research shows that the tree contains an anti-depressant effect
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Classic legume pods… a sign that this is a nitrogen-fixing plant!

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The Silk Tree attracts a lot of beneficial and beautiful insects. 

USING THIS PLANT

Primary Uses:

  • Ornamental Plant – this has been one of its primary uses around the world due to its showy, fragrant flowers and attractive leaves
  • Nitrogen Fixing Plant – this plant creates its own nitrogen through a symbiotic relationship with microorganisms (bacteria) in its roots. It typically produces an excess of nitrogen that can be used by neighboring plants.
  • Edible Leaves – Considered a potherb (a plant used as a vegetable or as a seasoning). Use when young, before they become fibrous. Aromatic. Dried leaves can be used for teas.
  • Edible Flowers – cooked and eaten as a vegetable.

Secondary Uses:

  • General insect (especially bees) nectar plant
  • Butterfly Plant – this plant has nectar that attracts Butterflies
  • Hummingbird Plant – this plant has nectar that attracts Hummingbirds
  • Fodder Crop – leaves, pods, and seeds – used for cattle, sheep, and goats
  • Wildlife Food – many animals will eat the pods and seeds (deer, squirrels, birds, etc.)
  • Wildlife Shelter – mainly birds and small mammals
  • Drought Plant – this species can tolerate prolonged dry conditions once established
  • Windbreak Species – fast growing, but not very tall, also it does not tolerate very high winds
  • Wood – used for furniture, cabinets, and other building applications (a few reports say it is a strong wood, but other say it is a weak wood… with this conflicting information, I would avoid using it for structures)
  • Fuel Wood – firewood, charcoal
  • Coppice Plant – while not a traditional coppice plant, this plant will grow back from the stump (or stool) and from the roots.
  • Pioneer Plant – helps reestablish overused or damaged land

Yield: no reliable information is available.
Harvesting: Not a tree that is typically harvested in a traditional sense. Flowers can be harvested in the Summer. Leaves can be harvested early for human food when young, and throughout the growing season for forage. The seed pods are formed in mid-late Summer and will stay on the tree into Winter; harvest when desired.
Storage: Use within a few days fresh. While I can find no information on storing pods/seed, I imagine they can be stored like any other dried bean to be used later.

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An ornamental pioneer species can make a renovation project more beautiful!

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Pods are great animal feed!

DESIGNING WITH THIS PLANT

USDA Hardiness Zone: Zone 7-9 for most varieties, but at least A. julibrissin f. rosea is hardy to -13F (-25C), which is Zone 6
AHS Heat Zone: 9-6
Chill Requirement: It is possible considering where this plant originates, but no reliable information is available.

Plant Type: Small Tree
Leaf Type: Deciduous
Forest Garden Use: Canopy Layer, Sub-Canopy Layer (only in a very open Canopy)
Cultivars/Varieties: There are a number of varieties, cultivars, and forms availabe

Pollination: Self-fertile
Flowering: Summer (June-July)

Life Span:
Considered short-lived, 30-45 years is typical, but may die back at 10 years, and may live much longer in optimal conditions (likely only in its native region)

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The classic leaves of a legume.

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A dark-leaved variety named “Summer Chocolate”

PHYSICAL CHARACTERISTICS OF THIS PLANT

Size: 16-40 feet (5-12 meters) tall and wide
Roots: Fibrous, sucker-forming
Growth Rate: Fast

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When allowed to grow on its own, it will form a dome shape and have multiple suckers.

GROWING CONDITIONS FOR THIS PLANT

Light: Prefers full sun
Shade: Tolerates minimal shade
Moisture: Prefers moist soils, but can grow in a dry conditions
pH: 4.0-8.0 (tolerates a wide range of soil conditions)

Special Considerations for Growing:
If you live in an area where wilt is common, consider growing a resistant variety (Charlotte and Tryon are two that know of)

Propagation:
Typically from seed. Scarification of the thick seed coat improves germination. Pre-soak for 24 hours in warm-hot water. Germinates in 2-3 months. Can be propagated by root cuttings (Winter), wood cuttings (Summer), and division of suckers (late Winter).

Maintenance:
Moderate. Need to monitor for seedlings and suckers.

Concerns:

  • Dispersive – self-seeding can produce many seedlings.
  • In some areas, there is a high amount of pests and disease (wilt and web worms are most common). This is a mixed issue… if the tree shoots up and then dies back due to pests/disease, then we have to ability to speed succession, but we need to be monitoring closely and planning well.

 

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Photo References:

  • http://upload.wikimedia.org/wikipedia/commons/6/68/Albizia_julibrissin_boubri.jpg
  • http://nursery.artknappsurrey.com/files/2010/10/Albizia-Mimosa-Tree-or-Silk-Tree-Julibrissin2.jpg
  • http://www.cas.vanderbilt.edu/bioimages/biohires/a/halju–frcloseup15438.jpg
  • http://upload.wikimedia.org/wikipedia/commons/2/27/AlbizziaJulibrissin2.jpg
  • http://upload.wikimedia.org/wikipedia/commons/2/2d/Mimosa-tree-Albizia-julibrissin.png
  • http://1.bp.blogspot.com/_GfiCvoODRto/TG4A61ElywI/AAAAAAAAAE0/sATTvlD9Zt4/s1600/IMG_3703.jpg
  • http://www.thompson-morgan.com/medias/sys_tandm/8797026320414.jpg
  • http://3.bp.blogspot.com/_oH7YVmRWh-s/SASv-kgyFwI/AAAAAAAABGw/QGqlfdqy7X4/s1600-h/Albizia+julibrissin+seed+pod.jpg
  • http://www.maltawildplants.com/MIMO/Pics/ALBJU/Albizia_julibrissin_[IMG_5130b].jpg
  • http://www.ibiblio.org/openkey/intkey/images/Albizia_julibrissin004.jpg
  • http://1.bp.blogspot.com/-lptyYtVFMUQ/Ud5UHXx9KxI/AAAAAAAAAOU/hIaSLrQ3zL4/s200/butterfly.jpg