Native to Korea and north-eastern China, tortured willow is a small, deciduous tree introduced to Australia as an ornamental for stabilising watercourses and road fill. Tortured willow's unique, twisted stems are popular for use as dried indoor decorations. Left to spread, it invades watercourses and the banks of rivers and creeks.
All species of willow are listed as Weeds of National Significance due to their propensity to invade native vegetation beside rivers and creeks. In urban environments, willows have aggressive root systems that damage footpaths and drains.
Tortured willow is a restricted invasive plant under the Biosecurity Act 2014.
- Twisted willow
- Short single-trunk tree up to 15m tall.
- Leaves are 5-13cm long, 1-2.5cm wide.
- Flower spikes are up to 2cm long.
- Catkins (flowers) are female.
- Stems are twisted.
- Found along banks of rivers and creeks.
- Not known to exist outside gardens in Queensland.
- Flowers in spring.
- Catkins (flowers) appear with first leaves after winter.
- Invades watercourses, riverbanks and creekbanks.
- Potential to cause stream management problems and reduce watercourse environmental value.
How it is spread
- Spread by broken twigs taking root downstream.
- Easily broken branches provide material for vegetative spread.
Effective control of willow trees can be achieved through a combination of mechanical and herbicide treatments, or by herbicide treatment alone. Choose control methods to suit your particular situation. All treated areas must be periodically checked and any regrowth treated, or the initial treatment efforts will be wasted. Follow-up must be undertaken to ensure a successful control program.
- Cut down individual trees.
- Burn all stems and branches (if permitted) as they can grow into new trees
Cut stump treatment
- Cut stems off horizontally as close to ground as possible and immediately (within 15 seconds) swab or spray cut surfaces and associated stem with herbicide mixture.
Stem injection treatment
- Make axe cuts at 5-7cm intervals all around stem (or stems), allowing undamaged bark between cuts.
- Make cuts below first branch and at an angle of approximately 30° to stem. Immediately inject up to 1mL of herbicide solution per cut, allowing solution to cover cut surfaces on both bark and tree.
See the WONS willow management guide for herbicide control and application rates.
No known biological control agents.
- Tortured willow is a restricted invasive plant under the Biosecurity Act 2014.
- It must not be given away, sold, or released into the environment without a permit.
- The Act requires everyone to take all reasonable and practical steps to minimise the risks associated with invasive plants and animals under their control. This is called a general biosecurity obligation (GBO).
- At a local level, each local government must have a biosecurity plan that covers invasive plants and animals in its area. This plan may include actions to be taken on certain species. Some of these actions may be required under local laws. Contact your local government for more information.
- Last reviewed: 31 Oct 2015
- Last updated: 21 Nov 2016