Basket willow

Basket willow is a deciduous shrub or tree no taller than 8m with petal-free flowers. It displaces native species and can block and flood waterways.

Description

• Leaves are usually alternate, lance-like to oval-like sometimes toothed.
• Flower clusters with no petals (catkins), are yellow or green, and occur before the leaves in early spring.
• Seed is wind dispersed. Vegetative spread from stem fragments and suckers, dispersed by water.
• Human-mediated dispersal through deliberate plantings.
• Habitats include wetlands, water bodies, water body margins, swamps, and wet areas behind coastal dunes.

What you need to know

Forms dense stands that compete with and displaces native species. Alters hydrology of waterways through blocking, flooding and structural changes. May alter soil decomposition cycles.

Management approach

Community Led

These organisms have not been legally declared as pests but may be of interest to the public as they occur regularly in the environment. They may be capable of causing adverse effects to the values of Waitaha/Canterbury.

Basket willow is declared an unwanted organism by the Ministry for Primary Industries (MPI) because it is capable of causing harm to the natural environment, physical resources or human health in Aotearoa/New Zealand.

These species pose a high risk to our environment, economy, recreation, and cultural values.

Consider removing these invasive species from your property and consult your local council for appropriate disposal. Consider lower-risk alternatives for your garden, such as native plants.

Control

Site management

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

Physical control

Dig or pull small plants out.

Plant parts requiring disposal: all parts.

Contact your local council for appropriate disposal locations.

Chemical control

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

Certified handler/experienced agrichemical user: 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 100mm stems drill two holes. For larger stems drill holes 150mm apart. Foliar spray with 150ml glyphosate per 10L of water and 20ml penetrant.

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

Biological control

Biological control is currently not available for this species.