When to Plant Komatsuna in Cairns, Tropical Guide
Soil temperature is modelled from Open-Meteo forecast (Cairns), not a live sensor.
What this month normally looks like in Tropical
In October the Tropical zone normally runs 34°C by day and 23°C overnight, with about 53 mm of rain over 5 or 6 wet days. Averages 1991 to 2026, 37 postcodes, SILO.
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This Komatsuna guide is written for the Tropical zone, which takes in Cairns, Townsville and Darwin. Somewhere else? Your postcode picks the right one.
Not your zone? Brisbane Sydney Melbourne Canberra Alice Springs Perth
Also handy: will it frost this week? and what grows in shade.
- Planting window
- Apr to Aug
- Days to harvest
- 35 days
- Sun
- Full sun to part shade
- Water
- Moderate
- Spacing
- 20 cm apart
- Soil pH
- 6.0–7.5
Komatsuna (Japanese mustard spinach) is a fast, mild leafy brassica that is ready in about 35 days and can be picked at any stage (Direct Compost Solutions).
Published · By GardenBuddy.au
Planting dates, current conditions and prices on this page update daily.
Photo: Wikimedia Commons
Planting Calendar for Tropical
- Jan -
- Feb -
- Mar -
- Apr D
- May D
- Jun D
- Jul D
- Aug D
- Sep -
- Oct -
- Nov -
- Dec -
S = Seed Tray T = Transplant D = Direct Sow
Want a nudge when it is sowing time?
One email a week with what is worth planting in the Tropical zone right now, Komatsuna included, plus which veg has jumped in price at the supermarket. Free, and you can stop it in one click.
How to Grow Komatsuna in Tropical Australia
- Soil
- Well drained soil with compost, pH 6.0 to 7.5 (Direct Compost Solutions).
- Salt
- Moderately sensitive. Copes with a little salt, but the harvest drops on salty bore water.
- pH Range
- 6.0-7.5
- Sunlight
- Full sun to part shade (The Seed Collection, Direct Compost Solutions).
- Spacing
- 20cm apart, 40cm between rows
- Watering
- Moderate, steady water (Direct Compost Solutions).
- Good companions
- Lettuce, Carrot, Radish
- 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.
Tropical Growing Tips for Komatsuna
Recommended Varieties
- Komatsuna (The Seed Collection)
Key Challenges
- Heat
Pro Tips
- Dry season only, part shade
Pests and problems for Komatsuna in Tropical
Harvesting Komatsuna
When ready: Any stage from baby leaf; full leaves about 30 cm long (Direct Compost Solutions).
How to harvest: Pick outer leaves and let the plant keep growing, or cut whole (Direct Compost Solutions).
Storing and preserving komatsuna
How to keep it
- Blanching and freezing. Blanch 2 minutes, cool, drain, pack (NCHFP). Keeps: 8-12 months.
What members get
- Soil and weather from your nearest station
- An email when it's time to sow
- Your own garden plan, including planning from a photo
- Price history and price alerts
- Pest risk alerts for your area
- Full salt and canning detail
Common Questions About Komatsuna
When do you plant komatsuna in Australia?
It depends on your climate zone, not the calendar month alone. Planting months by zone:
- Tropical (Cairns): Apr to Aug
- Subtropical (Brisbane): all year
- Warm Temperate (Sydney): all year
- Cool Temperate (Melbourne): Mar to May, Aug to Nov
- Cold / Highland (Canberra): Mar to Apr, Sep to Nov
- Arid / Semi-Arid (Alice Springs): Mar to Sep
- Mediterranean (Perth): all year
Can you grow komatsuna all year round in Cairns?
No. In the Tropical zone the planting months are Apr to Aug. Outside that window it either bolts, sulks or gets cut down by the weather.
When should I plant Komatsuna in Cairns?
You might be able to grow it here under the right conditions. Sow direct April to August in the dry season; komatsuna cannot take long spells of extreme heat (Direct Compost Solutions). Pick outer leaves young. No tropical source; months derived from the 10 to 25C range the supplier gives.
What soil temperature do Komatsuna need?
Komatsuna germinate best when soil temperature is between 7°C and 23°C.
How do I know when Komatsuna are ready to harvest?
Any stage from baby leaf; full leaves about 30 cm long (Direct Compost Solutions).
What are the best Komatsuna varieties for Cairns?
Recommended varieties for the Tropical zone include: Komatsuna (The Seed Collection).
What grows well with Komatsuna?
Good companion plants for Komatsuna include: Lettuce, Carrot, Radish.
Are komatsuna salt tolerant?
Only a little. Komatsuna are moderately sensitive to salt, so the harvest drops on salty bore water. Mix salty water with rainwater, and mulch the bed.
Which zone am I in?
Type your postcode into the box near the top of the page and it 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 Tropical zone, Cairns is its reference city.