More than 140 people attended the Grow West event, a state project to revegetate land. Indigenous varieties were planted over three hectares.

The 6300 plant milestone achieved two things: it is one-tenth of the number of trees Grow West hopes to plant this year, and about one-tenth the number Conservation Volunteers Australia, which manages the James Island Reserve, hopes to plant on the site.

Sunbury resident Maria Cossum said she joined the planting team to help "make a difference to a very degraded area" .

"I was thinking about the future of the area and wanted to ensure that in time it will become a great spot for bird watching."

Grow West's Trevor Prowd said 5000 trees were planted by lunchtime.

"The ground was soft and the day wasn't as harsh as Myrniong can be this time of year, which just made it that bit easier."

Members from the Friends of Werribee Gorge and Long Forest Mallee, the Victorian Mobile Landcare Group, the Myrniong Lions Club and the Victorian National Parks Association were among those who lent a hand.