Willow
Salix spp.
Declared Noxious Weed
Origin: Western Europe
Size: Up to 20m H
Best removal time: August to March
Flowers: August to October
Fruits: November to January
What it does
Willow trees cause great devastation along our waterway - they invade areas, overpowering the native vegetation. Their root systems clog the waterways and deciduous leaves increase the nitrogen levels in the water, killing many aquatic species and degrading water quality.
What it looks like
There are at least four species of willow which have become environmental weeds within the Yarra Ranges. These trees can grow from around 5m to 30m or more and can have both single or multiple trunks. Some willows are droopy with long thin stems, but other species are more upright. Leaves are light green to dull green, long and thin or smaller, broader and greyish as with the most common local willow, Grey Sallow. Tiny flowers are clustered on flowering spikes (catkins).
Declared noxious weeds have the potential to spread widely and cause serious economic loss to agriculture, or have some detrimental effect upon people, animals, the environment or the local community.
How it spreads
- by seed which is easily transported by water, wind, on machinery and also through soil contamination
- resprouts from small branch segments even if mulched
- regrow from discarded branches
- sold in nurseries and markets
Removal
Remove by hand
Trees less than a metre can sometimes be removed by hand, just ensure that the roots are removed as well otherwise it will continue to grow. Cut and paint is a more thorough method.
Cut and paint
This method is best for trees that are too large to hand pull and too small to drill and fill. Cut the tree off at ground level and paint the stump immediately with an undiluted glyphosate-based product.
Drill and fill
Drill holes close to the base of the trunk on a 45-degree angle to a depth of around 2-3cm. Fill each hole immediately with undiluted glysophate-based product. The tree will die slowly and will need to be removed later, however, retaining the root system is advisable to reduce soil erosion.
Indigenous alternatives to plant
Many tree alternatives exist that are indigenous to the Yarra Ranges region and would make great substitutes for Willows. Some alternatives include:
How to dispose of weeds
By disposing of environmental weeds correctly you can prevent re-infestation on your property and elsewhere.
- Landfill (Weed Wipeout Tip vouchers available for some species).
- Green waste bins ensure that weeds are not able to spread.
- Woody weed stems can be bundled for green collection twice per annum.
- Composting (excluding seed heads or species with vegetative reproduction, e.g. Wandering Trad).
- Burning in accordance with Council and the Country Fire Authority (CFA) prescribed burning periods and regulations.
- Recovery and transfer stations available for weed tipping are Healesville, Wesburn, Coldstream, Lysterfield and Montrose.
Using chemicals
Non-chemical treatment is often the most effective and safe option especially on smaller scale infestations.
Where chemical use is undertaken:
- Always follow the manufacturer’s guidelines when using chemicals.
- Wear protective clothing and eyewear.
- When purchasing your herbicide, always ask for a Materials Safety Data Sheet (MSDS) or refer to the manufacturer’s website for specific safety guidelines and information.
- Some herbicides will kill other plants and not just the target species.
- When used near waterways herbicides can be very poisonous to aquatic life.
- Use chemicals sparingly and be sure that you are using the right chemical and application technique.
- Ensure the weather conditions are suitable (e.g. minimal wind and no rain expected).
- Apply herbicides at the correct time during the plant’s growth cycle so you get the best results.