Too mulch of a good thing

The City is no longer able to provide free mulch. Here are some reasons why:

Polyphagous shot-hole borer

In November 2021, the City was included in the quarantine area for Polyphagous shot-hole borer (PSHB). 

The City was required to stop providing free mulch to residents as part of the quarantine order to help prevent the spread of this exotic pest, which can have a significant impact on urban trees, native trees and certain industries.

For more information about quarantine requirements or how to report a PSHB sighting, please visit agric.wa.gov.au/borer. 

Groundwater contamination

The halt on free mulch prompted the City to review its practice of stockpiling and making mulch, which is made from prunings of City trees and shrubs and green waste collected from households. 

Stockpiled green waste and mulch is identified as a potential environmental threat to superficial aquifer groundwater supplies due to the possible leaching of nutrients. 

The City’s free mulch pile was kept on the grounds behind the Recycling Centre. Over time, it starts to break down, which has the potential to leach nutrients into groundwater. 

Fire hazard 

Mulch piles in any location are considered a potential fire risk due to possible spontaneous combustion.

The location of the City’s mulch stockpile was difficult for emergency vehicles to access after-hours and presented a threat to nearby infrastructure and equipment.

Mulch remains an important part of the City’s garden maintenance and residents are encouraged to continue using mulch to prevent water loss from soil and erosion, reduce weeds and improve soil and plant health.

For more recycling initiatives, please see our Recycling Programs page.