The project known as Buffers to Bushland was formed with a plan to establish patches of native habitat across the city.
In test cases, this technique had proven to increase biodiversity more effectively than placing all the focus on a few dedicated reserves.
Mayor Glenn Docherty said populations of native plants were made stronger by this joint effort between Council and community.
"It's fantastic to have reached a milestone of 300,000 plants," said Mayor Docherty.
"Biodiversity equals better outcomes for our climate and environment so it remains a key focus for all our natural and man-made landscapes."
Rural property holders within the City of Playford with appropriate acreage, local community groups and schools can order boxes of mixed native tubestock suited to their zone.
These plants address a variety of land management issues, set up wildlife corridors and increase the city's overall biodiversity.
Each May, Playford's environment team and volunteers box the native plants and invite eligible groups to pick them up and plant them on their properties. The plants used in the scheme are propagated at an onsite nursery and are supplemented with seedlings from conservation charity Trees For Life.
Elizabeth Park Primary School has been collecting their boxes of native plants since 2018, using them in lessons to educate students on planting and native botany.
The school's Environment Specialist Will Cheesman said some plants had been used in their Bush Tucker Garden project.
"Students can get involved in planting around the school grounds. This opportunity gives them native revegetation experience which is a great way to expand on their skills," said Mr Cheesman.
"We're expanding the Bush Tucker Garden to include more Buffers to Bushlands plants. The students like digging holes so planting the natives is super fun for them."
If you own or manage a rural property, work for a school or part of a community group you can place plant orders in March and April at no cost. Plants are available in boxes of 50, with the mix of species determined by what is suitable for the location or the biological zone of the property registered.
