Margaret River Region residents are being recruited in the fight against the invasive weed Sweet Pittosporum, which threatens the region's iconic karri forest.
Nature Conservation Margaret River Region (NCMRR) says the battle must now be fought in backyards and private gardens, which are spreading the seeds and reinfesting remnant bushland.
Many residents on bush blocks and rural properties have joined a groundswell of effort to combat another invasive weed - the arum lily - in recent years.
NCMRR biodiversity project officer Mike Griffiths said Sweet Pittosporum also posed a grave risk to local bushland, particularly the Nguraren Kalleep Reserve, just north of Margaret River and formerly known as the A Class Reserve.
A native east Australian tree that grows to 12 metres, Sweet Pittosporum has coarse grey bark and glossy green elliptical leaves similar to bay leaves. The small, white, highly fragrant flowers occur in spring and early summer, followed by orange grape-sized fruit containing seed that are spread by birds.
"For many years, volunteers in our friends of reserves groups have been working to combat Sweet Pittosporum in Nguraren Kalleep Reserve," Mr Griffiths said.
"But we've identified it on private properties nearby, which pose a high risk of seeding back into the reserve and undoing the good work. So we really need locals to join the effort to control this weedy tree."
Mr Griffiths said Sweet Pittosporum was harmful because it threatened forest by outcompeting slower growing native plants.
"It takes over the understory and then as the plant matures it shades out the upper story too," he said. "Left unchecked, it even affects our karri forest because young karri seedlings can't compete."
To help local residents, NCMRR is holding a free, practical and hands-on community workshop on how to identify, remove and control Sweet Pittosporum on their properties.
It runs on Friday, May 27 from 9am-11am and is hosted by bush regenerator Rick Ensley and NCMRR staff Mike Griffiths and Jodie Passmore in bushland at the end of Valley Rd, Margaret River.
Tickets are free but places are limited, so email jodie.passmore@natureconservation.org.au to secure your spot.
"We'll cover how to effectively identify this species, how to hand pull it and also how to safely apply herbicide. And in doing so we'll learn more about the threats to our forests and reserves, and how we can all help," Mr Griffiths said.
"We'd love to see any residents attend, particularly if you live near Nguraren Kalleep Reserve or on the north side of the Margaret River township."