Albizia native range – and places where it’s invasive now, too

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Flowers that look like miniature fireworks are why botanists planted the silk tree (Albizia julibrissin) in gardens and parks all over the planet. Away from its native Central and East Asia, though, any suitable climate lets it spread fast and displace native trees, which is why several American states have outlawed its planting and sale.

It’s officially an invasive weed in the United States. These maps show what the native range of Albizia is. For the United States, more detailed maps show where the tree has been sighted. Perhaps you can join in on efforts to help control it!

Although not as prolific a seeder as other trees such as invasive tamarisk, this particular species of mimosa tree has seeds that can stay dormant for a very long time. Like the non-native Russian olive tree, it also grows back vigorously when chopped down.

Native range map of Albizia julibrissin

Albizia julibrissin, also called the silk tree, grows natively in Central and East Asia.

Thanks to its nice flowers that look like miniature fireworks, botanists started planting it all over the planet in gardens and parks. They thought it would make for a swell ornamental. In reality, whenever the climate is suitable, the tree spreads fast and displaces native trees.

Today, efforts are underway to limit and control it. Such regulations are only well-structured in a few states in the southeast of the United States. Elsewhere, as in Australia and Canada, the species is still under observation.

Map of where the Albizia mimosa tree comes from

Native range: Afghanistan, Bhutan, Bangladesh (likely), China, India, Iran, Japan, Korea, Myanmar, Nepal, Pakistan, Taiwan

Official Albizia sightings in the USA

The Early Detection and Distribution Mapping System, managed by the University of Georgia (USA), tracks and maps out any sightings of Albizia julibrissin. You can help out and submit sightings in your area here.

Their map is accurate down to county level. Here is the up-to-date version:

• Photographs of a plant’s leaves, flowers and seed pods taken at the site record diagnostic features that often wilt, shrivel or drop off during transport, making later identification easier.
• Where a recording scheme does route submissions through a reviewer before publishing them on its map, a sharp photo and an accurate location point make that check easier and usually quicker.
• The flat papery pods cling to the bare branches long after the leaves drop, which makes a silk tree easy to spot and confirm outside flowering time.

Albizia region by region: native, invasive or still watched

Whether albizia is a welcome tree or a regulated weed depends entirely on where you garden. Here is how its status differs from one part of the world to another, according to the maps and records quoted here.

In short, structured regulation is so far the exception rather than the rule, which makes reporting sightings all the more useful.

Legal status of Albizia as an invasive plant (USA)

This problem tree has spread through the SouthEast of the country. Several states have outlawed propagation, planting and sale of the plant. In pink, red and black: states that have passed laws or regulations to control the spread of this non-native mimosa tree.

• Before buying a silk tree, check with your state department of agriculture or cooperative extension service, since plant sale restrictions and invasive-species designations vary from state to state in the U.S.
• Some states place Albizia julibrissin on an advisory or watch list only, which discourages planting without making it an offence.
• Passing on albizia seed or seedlings to a gardener in a state where the tree is prohibited can breach that state’s plant rules, so keep the pods out of seed swaps.