Some gardeners may not be sure whether they are in a Temperate or Cool climate and, where frosts occur, the position of a property within a neighbourhood (the microclimate) can affect how much frost may affect your garden. The diagram below indicates where frost is more likely to affect parts of your garden.
The position of garden beds can also have a marked effect on the amount of plant damage that frosts cause. Cold air, like water, always flows downwards; anything that blocks the downward flow will result in frost damage in that area. Buildings, solid fences and shrubbery, and flat land at the bottom of a slope can all allow cold air to pool, and plants in these areas are more likely to be damaged by frost.
In temperate climates areas that can be affected by frost, gardeners may find it helpful to use the guide for ‘cool climates’ in autumn and winter and use the ‘temperate climates’ guide in spring and summer because the world’s climate is changing and we have recently experienced harsher winters and hotter summers. It appears that the standard climate zones may have to be adjusted slightly in future. If unsure about what to plant at a particular time of year, a reputable local nursery will have suitable plants in stock and be able to advise you on what is best for your local microclimate. Be cautious though when buying seedlings from Australia-wide nursery chains, as some tend to send the same seedlings to stores in all climate zones.
By the way, advice to orient beds in a north/south direction to allow plants to receive ample sunlight comes from northern hemisphere gardening practices and only applies to very cool climates in Australia. Most areas of Australia get more than enough sun to ripen crops. In fact, plants can benefit from some relief from harsh afternoon sun in warmer climates during summer months. It is more important to position beds across any slope in the ground to ensure that all plants in a bed have equal access to water. Avoid placing vegetable garden beds under trees, as trees are very competitive for both moisture and nutrients.