Salix spp.


Family: Salicaceae

Origin: Various

Regional Pest Management Plan (RPMP) status

  • Not a legally declared pest

View more about the RPMP statuses

General description

Mostly deciduous trees and shrubs. Roots are large, fibrous and often stoloniferous. Leaves are usually alternate, lanceolate, pointed at the tips and toothed. Flowers are catkins and borne in spring.

What you need to know

Although willows are not legally declared pest plants (except for Salix fragilis and S. cinerea), they may still be invasive in some situations. Consider lower risk alternatives for your garden, such as native plants.


Water body margins, wet places.


Seeds dispersed by wind and water. Vegetative spread from stem fragments. Human-mediated dispersal through deliberate plantings.

Impact on environment

Can form dense stands, outcompeting and displacing native plants.


Site Management

Follow up treated areas 3 times per year. Encourage natural regeneration of native plants or replant treated areas where possible after 2-3 treatments to establish dense ground cover and minimise reinvasion.

Recommended approaches

Physical control

Method: Dig out.

Plant parts requiring disposal: All parts.

Disposal options: Remove to greenwaste or landfill if practical.


Biocontrol is currently not available for this species.

Community agrichemical control recommendations

No qualifications: Cut stump and paste freshly cut base of stems with glyphosate gel. Cut material must be removed or it will regrow. Or cut stump and spray freshly cut base with 250ml glyphosate green per 1L of water. Cut material must be removed or it will regrow.

Basic Growsafe certified: Drill and inject trees with 500ml glyphosate per 1L of water if safe to do so. Drill 18mm holes (tangentially angled downwards) in a spiral up the trunk. For 50mm stems drill one hole. For 100mm stems drill two holes. For larger stems drill holes 150mm apart.

Certified Handler/Experienced agrichemical user: Foliar spray with 150ml glyphosate green per 10L of water and 20ml penetrant.

Safety notes

Large trees must not be drilled that are closer than 1.5 times the height of the tree from paths, walkways and property.

Trees over 4 metres in height should be treated and then removed by a qualified arborist.

Caution: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.

Hand holding Crack Willow stem.
Willows love wet feet and thrive on the banks of streams, wetlands and ponds. It forms a large tree that loses its leaves in winter.
Photo credit: Mary Ellen (Mel) Harte,
Crack Willow stem tips.
Most willows have flowers that are called catkins and appear in spring. Not all willow species are considered pests in Auckland but they have the potential to be weedy.
Photo credit: Barry A. Rice, The Nature Conservancy Wildland Invasive Species Team
Mature willow tree.
Willows are generally fast growing and can create large canopies that shade out streams and native plants. Roots and trunks will grow into stream and can change the flow of water.
Stand of young willows on the edge of a lake.
Some willows can regrow from roots that have been cut or from branches that have broken off and washed downstream. Willows can create viable seed that is carried downstream.