When to Plant Kohlrabi in Canberra — Cold / Highland Guide
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.
Planting Calendar
| 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
Current Growing Conditions
Soil temperature: 18.9°C (optimal range: 10–30°C) ✓ Ready to plant
How to Grow Kohlrabi in Cold / Highland Australia
When to Plant
September to February. Start indoors in punnets from August. Direct sow once soil warms above 10C.
- 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
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
Organic prevention: Net crops immediately after planting or sowing. Interplant with strong-scented herbs. Inspect leaf undersides for eggs every few days.
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