Tropical and Equatorial Zones:
The Hot Humid Zone includes the coast of the Northern Territory, Western Australia north of Broome, Cape York and the northern part of the Queensland coast above Mackay.
The temperature is high all year round; no frost occurs; average annual lowest temperature is 15°C. It is distinctive for its monsoon or ‘wet season’ and ‘dry season’ with most rain occurring in the ‘wet season’, which corresponds to summer in southern Australia. The wet season is hot and humid with an average January maximum temperature > 30 degrees C. The ‘build-up’ to the wet season (November) is the least comfortable time of year; temperatures are generally at their highest and humidity is also high, without the benefit of cooling rainfall. Living in the tropics has unique challenges for new gardeners, particularly if they didn’t grow up there. It is hard to understand that monsoon rain can be a battering force; that pest numbers can explode in days with a crop completely destroyed, that termites will attack the fruit trees you plant. Understanding what to plant is challenging and will mean accepting a whole range of new vegetables as part of your diet but it can be done. Mainstays of food production in a tropical garden are perennial plants including sweetleaf, winged bean, sweet potato, choko, yams, kangkong and pawpaw. Leonie Norrington’s book Tropical Food Gardens is a very good place to start and essential reading for all tropical gardeners. More information on seeds for hot humid areas. Vegetable sowing calendar for Darwin.
The subtropical zone includes the eastern coastline from Coff’s Harbour in northern NSW, Brisbane and north to Mackay. In WA it is approx. the coastline north of Exmouth to Broome and inland to Halls Creek.
It is a mild climate, which is why SE Qld is the fastest growing area in Australia. It has a low winter rainfall and reliable summer rainfall; high humidity from November to March; frosts are rare; average annual lowest temperature 10°C. Warm, humid, wet summer, average January maximum temperature < 30 degrees C. Living in the subtropics doesn’t mean that temperate vegetables will not grow, it just means you have to grow them in the winter and early spring and by November be switching to planting tropical vegetables to grow over the wet season. It is important to plant cool season crops so they have time to mature in the cool weather; if they are planted too late they will bolt to seed as soon as the weather warms up in spring. The subtropics grows tubers extremely well, particularly plants like sweet potato, cassava, Qld arrowroot, yacon and jicama. It shares with the tropics a wide range of perennial vegetables that are the staples of the subtropical vegetable garden.Month-by-month planting guide for south Queensland coastal areas by Brisbane Organic GrowersWide variety of information and links for gardening in SE QLD
Desert and Grassland Zones
Inland Australia is a challenging environment for gardeners as it has very high summer temperatures; very high evaporation; a dry summer with prolonged drought is common. The northern part has a hot, dry summer and mild winter; the southern part a hot dry summer and cold winter with an average annual lowest temperature of -5°C. Establishing a garden area under shadecloth can make all the difference in preventing lettuce and other greens bolting too soon.Vegetable sowing calendar for Alice Springs.Vegetable sowing calendar for western districts of Victoria.More info on shadecloth growing in inland areas.
Temperate Zones are often further divided along rainfall and minimum temperatures lines as a guide for gardeners:The above map shows all three as one zone.
Warm Temperate Zone
The warm temperate zone includes inland Queensland, New South Wales tablelands, the coastal region south of Sydney and north to Coff’s Harbour. In WA it is approx. the coastline south of Exmouth to Geraldton and inland to Meekathara.
Cool winters with light frost, usually non-existent on the coast. The ocean moderates temperature allowing coastal zones in warm temperate zones to grow a range of plants including subtropical ones. The rainfall is reliable year round; average annual lowest temperature 5°C. Warm summer, average January maximum < 30 degrees C. Temperate zones experience the distinct four seasons. Where frost does occur it is both a limitation and a blessing as it can have a significant effect of reducing pest numbers of fruit fly etc. Frost is also said to sweeten certain vegetables such as parsnips and cabbage. A true winter induces dormancy of plants including herbs such as comfrey and the plants seem to do better for the rest. A winter chill factor allows for successful growing of fruit trees that require this.
The mediterranean zone includes much of southern coastal Australia from Melbourne, Adelaide through to Perth.Characteristics:It is shares many of the features of the Warm Temperate zones, except for rainfall which is predominantly in winter with a low summer rainfall. The winter is cool, average annual lowest temperature 5°C. The summer is warm but with a low humidity which favours the growing of grapes and figs that are damaged by moisture and prone to fungal disease in wetter areas. Vegetable sowing calendar for South Australia.
Cool Temperate & Alpine Zone
This includes Tasmania, Canberra and the ACT, all high mountain areas including the Granite Belt of SE Queensland, the high areas of the NSW tablelands (Armidale, Glen Innes), the Southern Tablelands of NSW and the high areas of Victoria.