The short version: Quick warm-season crops still fit into January in most zones: choose fast varieties and sow into shade. Temperate and cool gardens also start winter brassicas in shaded trays. The tropics are at the height of the wet, arid gardens are too hot for much until late in the month, and cool and alpine gardens are at their busiest. Pick before every heatwave.
By January the beans hang in bunches and the zucchini are winning, yet the seed sown in these weeks decides the April and May harvest.
The catch is heat: a bare seedbed in summer sun runs far hotter than the air, and seed sits idle or cooks.
Getting seed up in hot soil
Lettuce seed can go dormant once the soil passes about 25Β°C, a response called thermodormancy, and carrot, parsnip and silverbeet come up patchy in hot ground. Four habits help:
- Sow in the evening, into a row soaked first, so seed drinks through the cooler night.
- Shade the bed with 30 to 50% shade cloth on hoops, with air moving underneath.
- Cover carrot and parsnip rows with a board or damp hessian, check under it daily, and lift it as seedlings show.
- Raise lettuce in punnets somewhere cool and shaded, and plant out late in the day.
What to sow in January, zone by zone
These zones are broad groupings: if your garden sits between two, go by local signs such as your first autumn frost. Our month-by-month sowing chart has more for each zone.
Tropical: Darwin in the Northern Territory, Cairns and Townsville in Queensland
The wet peaks: Darwin Airport averages 432 mm of January rain, Bureau of Meteorology records show, enough to wash small seed away. The Northern Territory Government suggests raising seedlings under cover from December to February and resting empty beds under thick mulch.
On raised mounds, sow Malabar (Ceylon) spinach, Egyptian spinach, yam bean and peanuts, plus winged bean on a trellis; many types flower as days shorten, so seed sown after Christmas loses little. Basil suits pots moved under cover. Amaranth waits for February, okra for March, and tomatoes, beans and lettuce for the dry. Our wet-season crop guide has more.
Subtropical: Brisbane and south-east Queensland, northern New South Wales
Sow cucumber, zucchini, squash, bitter melon, okra, amaranth and kang kong for autumn, plus pumpkin on frost-free coasts. January is the last month for eggplant and capsicum, and on the coast for sweet potato slips, dug from late autumn into winter. Tomatoes can go in again, avoiding the wettest weeks. Bean fly hits young beans hardest in their first three to four weeks, so check seedlings closely.
Arid and semi-arid: Alice Springs in the Northern Territory, Broken Hill in New South Wales, Mildura in Victoria, Kalgoorlie in Western Australia
January is the hottest month inland, with Alice Springs Airport averaging a 36.6Β°C maximum: too hot for most sowing in open ground, so carrots, lettuce and most brassicas wait for February and March. Late in the month comes a second planting for autumn: zucchini, squash, cucumber, amaranth and kang kong, plus tomato and capsicum seedlings raised in shade. Bush beans do better in February, flowering after the worst heat. Frost returns from May, so choose fast varieties.
Temperate: Sydney and the New South Wales coast, Melbourne in Victoria
Sow bush beans to pick from about March, and the last sweet corn, cucumber, zucchini and squash early in the month. Sow shaded rows of carrot, beetroot, radish, swede and turnip for autumn. Silverbeet and slow-bolting lettuce want afternoon shade, and early seed potatoes can go in for an autumn crop. Start winter brassicas, below. Eggplant is finished: January seed would crop into cooling autumn nights.
Mediterranean: Perth and southern Western Australia, Adelaide in South Australia
Dry heat makes January quieter, and every seedbed needs shade and a daily moisture check. Sow beans and short rows of carrot, parsnip, beetroot, turnip, silverbeet and lettuce; Perth sands grow carrots in any month. Cucumber has its last sowing in both cities and sweet corn in Adelaide, while Perth can sow zucchini into March.
Cool and alpine: Tasmania, Canberra in the ACT, Ballarat in Victoria, Orange and Armidale in New South Wales, Stanthorpe in Queensland
January is the heart of the season. Bush beans, zucchini and squash have their last call, in quick varieties. Sow broccoli, cauliflower, cabbage and kale for autumn and winter, and carrot, beetroot, parsnip, swede, turnip, silverbeet, lettuce and radish. Tomatoes and cucumbers are too late from seed, though coastal Tasmania can sow a last quick sweet corn.
Start the winter brassicas, out of the heat
Temperate and cool gardens start broccoli, cauliflower, cabbage and kale in January for late autumn and winter, and Mediterranean gardens cauliflower and Brussels sprouts. A seedling checked by heat or dry soil can bolt or form a tiny early head, so raise them in trays under shade cloth, harden them off over a few days and plant out late in the day. Mesh the bed from the start against cabbage white caterpillars. Elsewhere most brassicas start between February and April.
Little and often: greens and carrots
Succession sowing keeps greens and carrots coming: sow a short row every two to three weeks, so one hot week bolts a few plants, not the lot. Established silverbeet copes with summer better than lettuce or spinach if watered, and in warmer zones greens that take the heat, such as Malabar spinach and amaranth, take over.
Harvest, pests and mildew in the heat
January is peak picking: take zucchini at 12 to 20 cm and beans every couple of days to keep them setting. Before a heatwave or a holiday away, pick everything ripe or nearly ripe, since an early pick beats scalded fruit on the vine; tomatoes that are just colouring ripen on the bench.
Aphids gather on soft young shoots, especially after a heavy nitrogen feed, and scale builds up on citrus and shrubs nearby. Hose or rub off small colonies, use soap spray in the cool of the morning, and skip oil sprays above about 30Β°C.
Powdery mildew on zucchini, pumpkin and cucumber thrives in a muggy summer, as its spores need humid air, not wet leaves. Remove the worst leaves, space vines for airflow, and water the soil early in the day.
Plan the autumn patch, and the year
Autumn crops must reach a good size before the cold slows them. Note which beds come free and keep the cabbage family off ground it used in the last two years; our autumn sowing guide has the windows. Plan the year around your zone, your space and what your household eats, with the Australian sowing almanac to hand.
Where our seed and tubers can go
Our sweet corn seed cannot go to Western Australia, Tasmania or the Northern Territory, many chilli, capsicum and tomato lines not to Western Australia, and a few tomato lines not to Tasmania. Due to quarantine restrictions and our shipping policy, we cannot send sweet potato tubers or seed potatoes to Western Australia, Tasmania or Kangaroo Island; Australian Interstate Quarantine explains why seed bought online is regulated between states.
A word of caution
Yam bean is grown for its root, because its seeds, pods and leaves are poisonous. Egyptian spinach seeds and pods are poisonous to people, cats and dogs. Keep both away from children and pets; if any is eaten, call the Poisons Information Centre on 13 11 26. With any spray, follow the label, including the wait before picking.
Frequently asked questions
Can I still sow tomatoes in January?
Sow seed in the subtropics for an autumn crop. Arid and Mediterranean gardens can still plant seedlings; temperate gardens are at the end of the window, cool gardens past it, and the tropics wait for the dry.
Is there time to sow honeydew or rockmelon?
Rockmelon and honeydew need 10 to 16 weeks of warmth. Arid and subtropical gardens can sow a quick variety early in January, though late subtropical vines meet mildew; cooler zones stop in December, and the tropics grow melons in the dry.
Why does my lettuce seed not come up in summer?
The soil is too hot: above about 25Β°C the seed can go dormant. Use the four habits above, and see our year-round lettuce guide.
Can I plant sweet potato in January?
On the subtropical coast, yes, as the last planting. In the tropics it is late: the main plantings go on mounds in November or December, or from April. Perth's window closes in January; elsewhere it is too late.
Sow small, sow in the shade and pick before the heat, and January sets up autumn as well as feeding summer.
Related growing guides
- Starting winter brassicas in summer heat
- Plan a year in the vegie patch
- Netting crops and fruit: exclusion nets, fruit bags and wildlife-safe mesh
- What to sow in February: vegetables for every zone
- What to sow in December: vegetables for every zone
- Herbs to sow in January, zone by zone
- Flowers to sow in January, zone by zone
- Summer vegetables for Perth and Adelaide
- Summer crops in a short cool-climate season
Find seed in our vegetable seed range, and tubers in the sweet potato tuber collection (not to Western Australia, Tasmania or Kangaroo Island).