Brisbane Local Food local online gardening site with forums and blogs. Some members participate in garden visits.
Jerry Coleby-Williams Gardening Australia presenter lives in Brisbane – strong advocate for the environment and responsible, sustainable gardening.
Kumbartcho Sanctuary Nursery Community nursery at Eatons Hill on Brisbane northside. Great source of tubestock natives. They also run some interesting workshops.
Pollinator Link a not-for-profit social enterprise creating wildlife corridors for urban spaces. The concept is to use backyards, parks, school grounds and even unit block balconies to link patches of bushland habitat fragmented by our urban environment.
More gardening sites from further afield
Gardening with Angus website of Angus from Gardening Australia has an emphasis on Australian native plants
Garden Drum has lots of good articles – many from an Australian perspective.