When to plant Swede in Subtropical Australia

Subtropical zone — applies to Brisbane, Gold Coast, Sunshine Coast, Coffs Harbour, Lismore and similar areas. Growing elsewhere? Temperate · Cool · Tropical · Arid.

Sow swede direct from January to May, plus November and December, dropping seed straight into a deep, loosened bed. Seed germinates fast in 6–12 days, and roots are ready to lift in 70–90 days. Sow 10 mm deep, then thin seedlings to 10–20 cm apart in rows 30–50 cm apart so the roots have room to swell. Swede is a cool-season root, so the autumn-into-winter sowings suit Brisbane and Toowoomba-region gardens best, giving sweet, dense roots that a hot, humid summer would never produce.

Sowing calendar — subtropical zone

Green months are your sowing window: November to May.

Growing notes

Swede does its best work in the cool months, so lean on the January to May sowings, which mature through the mild subtropical winter. The late spring window is workable but riskier, as roots forming into building summer heat and wet turn woody and split.

The most common problem is roots that stay small and tough. This comes from crowding, dry spells, or sowing into the heat, so thin early to 10–20 cm and keep water steady and even. Uneven watering, in particular, causes splitting after the storms that mark the wet.

Swede is a brassica, so it draws cabbage moth, aphids and, in humid conditions, downy mildew. Exclusion netting over the bed is the cleanest fix, keeping moths off before they can lay. Rotate away from beds that grew other brassicas last season to reduce clubroot and pest carryover. In Lismore and Sunshine Coast gardens, work in some lime before sowing, since sweet, well-limed soil discourages clubroot and helps the roots size up evenly. Harvest while roots are still tender, around fist size, rather than leaving them to go pithy in the ground.

Swede at a glance

Common questions

When is the best time to plant swede in the subtropics?

Sow from January to May for roots that mature through the cool, dry winter, which gives the sweetest results. November and December sowings are possible but risk woody, split roots in summer heat. Autumn is the safest bet.

Why are my swede roots small and woody?

Crowding, heat, and irregular watering all cause tough, undersized roots. Thin seedlings to 10–20 cm apart, sow into the cooler months, and keep moisture steady. Harvest at around fist size before the roots go pithy.

Do swedes get attacked by cabbage moth?

Yes, swede is a brassica and cabbage moth caterpillars will chew the leaves. Fine exclusion netting laid over the bed is the most reliable defence, keeping moths from laying in the first place. Check under leaves regularly if you skip the netting.

How do I stop swede roots splitting after rain?

Splitting usually follows a dry spell then a sudden downpour, common in the subtropical wet. Keep watering even and consistent, and mulch to buffer the soil. Harvesting roots before heavy storm periods also helps.

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