The Sir Joseph Banks Medal competition, which has been running since 2008, recognises the city's best biosustainable gardens as well as nature strip redevelopments.

The residential award this year was taken out by Donna and Joe Nicholl for their garden in Mount Austin, while the award for best nature strip was won by Sue and Peter Lyzun for their work in Bourkelands.

Wagga mayor Rod Kendall served as the medal's patron this year.

He said with Wagga often experiencing hot, dry summers, it was important for home gardens in the city to become more sustainable.

"It's particularly important we keep in mind our water use in our gardens - we do have a limited water supply," he said.

"As Wagga continues to grow, we'll need to make that water go further."

Winners in previous years have shown a dramatic curbing of water usage, with one garden that had previously entered the competition in Kooringal reducing its water usage by 85 per cent.