Growing Kohlrabi in Australia: The Complete Guide

Kohlrabi is an easy brassica to grow, needing full sun with consistent watering.

Kohlrabi is one of the easy additions to a home garden, and this article walks through everything behind our one-page printable guide in a good deal more depth than a single card allows.

Before the how-to, a word on why kohlrabi is worth growing in the first place. At a glance, it's rated easy, with a sun of full sun; water of consistent; soil ph of 6.0–7.0 — details that matter more once you're actually planning around them than they do on a first read. The rest of this article works through exactly what each of those means day to day, in more depth than a single printable card has room for, and with the reasoning behind each recommendation rather than just the recommendation itself.

Climate and Timing Considerations

Australia's climate zones change growing timing more than most general advice accounts for. Cool temperate zones (Tasmania, the Victorian highlands, southern NSW) have recurring frost risk well into what other zones call spring, which compresses the safe planting window for frost-tender plantings. Warm temperate zones (Sydney, Adelaide, Melbourne, Perth) sit closest to what general advice assumes by default. Subtropical zones (Brisbane, northern NSW) rarely see frost at all, and the growing calendar shifts earlier and later as a result. Our site-wide zone setting adjusts the advisory note shown on the Planting Calendar for exactly this reason — worth setting once if you haven't already. The same zone setting also feeds the Harvest Calendar, so both ends of the growing cycle reflect wherever you actually garden, rather than a generic Australia-wide average.

• Cool Temperate (TAS, VIC highlands, southern NSW, ACT): shorter frost-free window — lean toward the later end of any spring planting window shown on the guide above.
• Warm Temperate (Sydney, Adelaide, Melbourne, Perth, coastal NSW/WA): closest match to the general timing shown above; frost is occasional but rarely severe.
• Subtropical (Brisbane, northern NSW, coastal QLD): minimal frost risk — often plantable a few weeks earlier and later than the general window shown above.

A stem that swells like a bulb

The edible part of kohlrabi is actually a swollen stem sitting just above soil level, not a root — an unusual growth habit among the brassicas.

How to Plant Kohlrabi

Method. Direct sow or transplant seedlings.

Soil. Rich, well-drained, moderately fertile.

Timing. Sow in cooler months for the best texture.

Taken together, these are the details that separate a smooth result from a frustrating one.

Ongoing Care

Worth paying attention to:

• Keep soil evenly moist — irregular watering causes woody bulbs.
• Harvest at the right size — overgrown bulbs turn tough.
• Net against cabbage moth.
• Mulch to keep the swelling stem cool and moist.

Getting these details right matters more than it might seem — keep soil evenly moist — irregular watering causes woody bulbs. Mulch to keep the swelling stem cool and moist. Treat this list as a routine to build rather than a one-off checklist, and it becomes second nature within a season or two.

Common Problems

Keep these points in mind:

• Cabbage moth — net or hand-pick.
• Woody texture — harvested too late; pick at tennis-ball size.
• Splitting — irregular watering.
• Clubroot — rotate beds, keep pH up.

Each of these compounds over a season — small misses early tend to show up later — cabbage moth — net or hand-pick. Clubroot — rotate beds, keep pH up. Treat this list as a routine to build rather than a one-off checklist, and it becomes second nature within a season or two.

When and How to Harvest

Signs. Bulb reaches 5–8cm across — larger varieties can go bigger without toughening.

Method. Cut at the base just below the swollen stem.

Curing. None needed.

Storage. Fridge crisper, 2–3 weeks.

It's worth reading these as a set rather than in isolation; they reinforce each other.

Preserving. See Fermenting for sauerkraut and fermented brassicas, or Freezing Produce for blanching and freezing a glut.

Companions & rotation

Our printable card above lists specific plants that pair well nearby and others best avoided, along with a rotation note: Onion, Beetroot, Tomato. Getting this right matters more over multiple seasons than it does in any single one — the benefits and the risks of poor rotation both compound over time rather than showing up immediately.

Related Guides

If kohlrabi suits your garden, these related guides in the same category are worth a look too:

• Bok Choy
• Broccoli
• Brussels Sprouts
• Cabbage

For the condensed, printable version of everything above, head to the main kohlrabi guide page. Companion planting and bed rotation both make a measurable difference over a season, and our Companion Planting Checker takes the guesswork out of both. As with every guide on this site, this is general information based on our own research and experience, not professional advice — your specific soil, climate, and circumstances will always vary from ours to some degree.

Beyond the printable card, our Planting Calendar and Harvest Calendar tools will show a zone-adjusted note for kohlrabi specifically, and the Companion Planting Checker covers the specific pairings mentioned above in more detail.

Frequently Asked Questions

→ View the printable A4 guide for kohlrabi