When to Plant Kohlrabi in Canberra, Cold / Highland Guide

Sow August to April. Right now in October you can sow.

Planting window
Start in trays from August. Sow direct from September to March once the soil is above 10°C, and plant out up to April.
Days to harvest
55 days
Sunlight
Full sun (6+ hours). Tolerates light shade, especially in warmer zones where afternoon shade prevents bolting.
Water needs
Consistent, even moisture throughout growth. Water deeply 2-3 times per week...
Spacing
20cm apart, 35cm between rows
Soil pH
6.5-7.5

This Kohlrabi guide is written for the Cold / Highland zone, which takes in Canberra, Cooma and Bright. Somewhere else? Your postcode picks the right one.

Not your zone? Cairns Brisbane Sydney Melbourne Alice Springs Perth

Also handy: will it frost this week? and what grows in shade.

Kohlrabi

Photo: Wikimedia Commons

Kohlrabi is technically not a root vegetable. The edible part is a swollen stem that forms above ground. Fast-growing (55-70 days), mild-flavoured, and versatile in the kitchen, kohlrabi is an underused gem in Australian gardens. It thrives in cool weather, handles light frost, and is one of the best brassicas for beginners. Both the bulb and leaves are edible.

See what grows now in your own postcode

Planting Calendar for Cold / Highland

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
S/T/D S/T/D S/T/D T - - - S S/T/D S/T/D S/T/D S/T/D

S = Seed Tray   T = Transplant   D = Direct Sow

Want a nudge when it is Kohlrabi sowing time in Canberra?

One email a week with what is worth planting in the Cold / Highland zone right now, Kohlrabi included, plus which veg has jumped in price at the supermarket. Free, and you can stop it in one click.

Current Growing Conditions

Soil temperature: 13.6°C (optimal range: 10–30°C) ✓ Ready to plant

Modelled from Open-Meteo forecast (Canberra), not a live sensor.

What this month normally looks like

In October the Cold / Highland zone normally runs 20°C by day and 7°C overnight, with about 58 mm of rain over 7 or 8 wet days. The coldest October night on record across the zone was -6.4°C, so a late frost is not out of the question. Averages 1991 to 2026, 15 postcodes, SILO.

How to Grow Kohlrabi in Cold / Highland Australia

When to Plant

Start in trays from August. Sow direct from September to March once the soil is above 10°C, and plant out up to April.

Soil
Rich, well-drained soil with plenty of organic matter. Prefers neutral to slightly alkaline soil. Dig in compost and well-rotted manure before planting. Add lime to acidic soils (critical for preventing clubroot).
pH Range
6.5-7.5
Sunlight
Full sun (6+ hours). Tolerates light shade, especially in warmer zones where afternoon shade prevents bolting.
Spacing
20cm apart, 35cm between rows
Watering
Consistent, even moisture throughout growth. Water deeply 2-3 times per week. Inconsistent watering causes the stem bulb to become woody and split. Drip irrigation preferred.

Companion plants: Beetroot, Celery, Cucumber, Dill, Lettuce, Onion

Avoid planting near: Strawberry, Tomato, Runner Bean

Grow before, grow after

Kohlrabi belongs with the brassicas, the leafy greens and brassicas turn of a four turn bed rotation.

Grow before it
Legumes (Beans - Dwarf, Peas, Broad Beans)
Grow after it
Fruiting crops (Tomato, Capsicum, Zucchini)

Give the bed 3 turns before brassicas go back in. The cabbage family is hungry for nitrogen and shares club root and other soil diseases.

Cold / Highland Growing Tips for Kohlrabi

Recommended Varieties

  • White Vienna
  • Purple Vienna
  • Early White Vienna

Key Challenges

  • Short growing season
  • Late spring frosts on seedlings

Pro Tips

  • Start early in punnets indoors. Transplant after last frost
  • Fast maturity (55-70 days) suits short highland seasons
  • Two crops easily possible: September start, January start

Harvesting Kohlrabi

When ready: Stem bulb is 6-8cm diameter (tennis ball size) for standard varieties. Bulb should feel firm and smooth. Harvest promptly. Overgrown bulbs (>10cm for standard varieties) become woody and fibrous. Exception: Superschmelz stays tender up to 20cm.

How to harvest: Cut stem just below the bulb with a sharp knife, or pull the entire plant. Trim off leaves (save for cooking, they are edible). Trim the root.

Common Kohlrabi Pests in Cold / Highland Zones

Fungal Soft Rot, risk: LOW (score: 20/100)

In the pest library for kohlrabi:

Cabbage White Butterfly, high severity

Organic prevention (Black Rot): Use certified disease-free seed. Hot water seed treatment (50C for 25 minutes). Avoid overhead watering. Crop rotation (3 years). Remove crop debris.

View all pest alerts →

Where to next

What kohlrabi costs in the shops right now, retailer by retailer, updated daily.

Also worth sowing in the cold and highland zone this October: Sweet Corn, Beetroot, Celeriac and Parsnip.

The pest most likely to find your kohlrabi: Cabbage White Butterfly.

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Common Questions About Kohlrabi

When do you plant kohlrabi in Australia?

It depends on your climate zone, not the calendar month alone. Planting months by zone:

Does kohlrabi grow all year round in Canberra?

No. In the Cold / Highland zone the planting months are Jan to Apr, Aug to Dec. Outside that window it either bolts, sulks or gets cut down by the weather.

Which zone am I in?

Type your postcode into the box under the heading and the page tells you, and links this crop in your own zone if it differs. Or look it up on the grow zone map. This page is the Cold / Highland zone, Canberra is its reference city.