Tropical planting calendar

What to sow each month

Each card lists the crops to sow or plant in that month in the tropical zone; the current month is marked. The calendar is busiest from April to July and almost empty in the wet.

The full chart

Every crop in the calendar, month by month. Green cells are the months to sow seed or plant seedlings in the tropical zone; the column on the right says the same in words.

sow or plantnot recommendedthis month

Wet and dry, not summer and winter

In the tropics the calendar turns on rain, not cold. Darwin gets 1,619 mm of its 1,737 mm a year between November and April – 93 % of it – and almost none from June to August. The pattern holds across the zone: 90 % of Townsville's rain and 91 % of Broome's falls in the same six months. Temperatures barely change. Darwin's average maximum sits between 31 and 33 °C in every month, and even July nights average 19 °C.

What changes is the humidity. Darwin's 3 pm humidity averages 70 % in January and 37 % in July. Most vegetables in this calendar come from cooler, drier climates: in the wet, fungal diseases thrive and leafy crops run to seed in the heat. The dry season, which lines up with the southern autumn and winter, is warm, sunny and dry, and that is when they grow. The NT Government's sowing calendar for Darwin and Katherine starts nearly every crop in April; its Katherine office calls the dry season perfect for most home vegetables, and Townsville City Council's garden guide calls the cooler, drier months from April to November ideal for planting.

The Bureau of Meteorology dates the start of the wet as the first 50 mm of rain after the dry season. Around Darwin that is usually in the last week of October, around Katherine in mid-November. False starts, where a storm is followed by weeks of dry weather, happened about 30 % of the time over the last 30 years, so the first big rain is not a signal to plant.

No frost: heat and rain set the limits

None of the tropical towns in the calendar has a frosty night in an average year. Darwin, Cairns, Townsville, Broome, Katherine and Karratha all average no nights at 2 °C or below in Bureau of Meteorology records, some going back to 1939.

Heat is the bigger risk, and it grows inland. Tindal, near Katherine, averages 152 days a year at 35 °C or above and Broome 63, against 14 in Darwin and 3 in Cairns. The Atherton Tablelands behind Cairns are the exception to the whole picture: they are high enough to be noticeably cooler and are closer to the subtropical calendar.

The tropical year for vegies

• April–May, as the wet ends: the big sowing months, with 36 crops in the calendar in April and 40 in May. Capsicum, chilli, eggplant, cucumbers, zucchini, pumpkins, melons, sweet corn and beans go in now, along with the cool-season crops the dry season allows: lettuce, English spinach, broccoli, cabbage, cauliflower, carrots, beetroot, onions and garlic.
• June–July, the heart of the dry: still busy. Tomatoes go in from May to July, most crops can still be sown in June, and July is the last month for many of them.
• August–September: the last sowings of cucumbers, zucchini, kale, cabbage, celery and Asian greens in August. By September only okra, sweet potato and basil are left.
• October–February, the build-up and the wet: harvest what is left, then mulch, compost and get beds ready for April. Green Harvest lists sweet potato, kangkong, winged bean and choko as wet-season staples; in this calendar only sweet potato and basil carry on through the wet, and beetroot can start again in March.

Towns in this zone

The tropical towns in the calendar, with the Bureau of Meteorology station behind each frost figure. Every one of them is frost-free.

Questions