Cold Frames and Cloches: Low-Cost Season Extension for Australian Gardens

Cold Frames: Unheated Mini-GreenhousesA cold frame is an unheated box with a transparent lid — essentially a portable mini-greenhouse sitting directly on the soil. In cool temperate Australian gardens, a cold frame provides: 4–6°C of overnight frost protection (adequate to protect most frost-sensitive crops down to -4°C outside); earlier spring seed germination (soil temperatures in a cold frame are 3–6°C warmer than uncovered soil); and a hardening-off environment for seedlings transit…