Frog Saunas: a simple solution to a deadly threat
Did you know you can help save endangered frogs right from your own backyard?
A recent episode of Gardening Australia featured Dr Anthony Waddle and Costa Georgiadis showcasing an innovative, backyard-sized solution to a deadly problem facing Australia’s frogs: the chytrid fungus. Their answer? The Frog Sauna, a simple structure that could become a life-saving tool for frog conservation.
What is a Frog Sauna?
The Frog Sauna is a compact, greenhouse-style structure designed to provide a warm, safe refuge for frogs during colder months. Why does this matter? Because chytrid fungus, a major driver of frog extinctions worldwide, thrives in cool, damp environments. By giving frogs a warm and dry microhabitat, especially through autumn and winter, the sauna can help protect them from infection and support population recovery.
Chytrid fungus has already pushed several Australian frog species to extinction and continues to threaten many more. But there is hope... and it could begin in your own garden!
Frog Saunas coming to the Georges River
Thanks to a $500 mini-grant from the Jane Goodall Institute, Georges Riverkeeper installed six frog saunas at selected locations across the Georges River catchment for a two-month trial which concluded in November 2025.
This initiative was made possible through the enthusiastic involvement of five volunteer groups, comprising more than 22 community volunteers, and over 25 students, who all assisted with installation, monitoring, and observations at each site. Their efforts have been invaluable in helping us better understand how local frog species use their habitats.
Although no frogs were directly observed using the saunas during this short trial phase, the project provided valuable insights into frog activity and habitat preferences. From twenty-six FrogID submissions, four species were scientifically verified in the surrounding habitats including the Peron’s tree frog, Common eastern froglet, Striped marsh frog, and the Eastern dwarf tree frog.
The lessons learned will inform future designs and site selections, with plans to reinstate the saunas in winter next year, when conditions are more favourable for frog activity.
We extend our heartfelt thanks to all volunteers, groups, and students for their enthusiasm and commitment to amphibian conservation within the Georges River catchment.
Build your own Frog Sauna
Want to be part of the frog-saving movement? You can build your own Frog Sauna at home. Here's how (adapted from Dr Anthony Waddle and Prof Rick Shine):
- Pick a spot: Choose a sunny, frog-friendly location with moist soil or water nearby. Edges of ponds or damp garden beds are ideal.
- Paint your bricks black: Let them dry completely. Black bricks absorb and retain heat. This is the key to warming the sauna.
- Build the base: Use the bottom of a small greenhouse frame to start your structure.
- Secure the setup: Use garden stakes, tent pegs or cable-tied bricks to anchor it against wind.
- Finish the frame: Pull the greenhouse cover over the top and fasten it using Velcro or ties. Leave a small gap at ground level so frogs can come and go.
- Listen for frogs: Use the FrogID app to record and report any frog calls. Your data helps scientists monitor local populations.
Bonus tips
- Saunas are most useful during cooler months when chytrid risk is highest.
- In summer, repurpose your sauna into a mini greenhouse for seedlings and benefit from natural frog fertiliser.
- Make sure the structure is tightly secured so it withstands storms and wind.
You can view a step-by-step infographic here. (Adapted from Anthony Waddle and Rick Shine.)
A simple act, a big impact
Saving frogs doesn’t always require high-tech labs or remote fieldwork. Sometimes, all it takes is a bit of backyard space, a handful of materials, and a commitment to protect the wildlife right under our noses.
Together, one Frog Sauna at a time, we can help create safe havens for our struggling amphibian neighbours.
