When to Plant Horseradish 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.
Jump to section
This Horseradish 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.
- Days to harvest
- about 21 weeks
- Sun
- Full sun to part shade
- Water
- Low
- Spacing
- 40 cm apart
- Soil pH
- 6.0–7.5
Horseradish is a robust, hardy perennial grown for its pungent root. Once established, it is almost impossible to eradicate. A feature or a bug depending on your perspective.
Published · By GardenBuddy.au
Planting dates, current conditions and prices on this page update daily.
Photo: Wikimedia Commons
Best Planting Window for Tropical
Horseradish is not recommended for Tropical.
Horseradish needs cold winters to make pungent roots and does not suit the tropics. Grow galangal or ginger for heat instead.
Want a nudge when it is sowing time?
One email a week with what is worth planting in the Tropical zone right now, Horseradish included, plus which veg has jumped in price at the supermarket. Free, and you can stop it in one click.
How to Grow Horseradish in Tropical Australia
- Soil
- Deep, loose, well-drained soil enriched with organic matter. Best roots form in sandy loam or loam dug to at least 30cm depth. Tolerates a wide range of soils but heavy clay produces misshapen roots. Remove stones.
- 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 (6+ hours). Tolerates partial shade but root development is reduced.
- Spacing
- 40cm apart, 60cm between rows
- Watering
- Moderate water needs. Water deeply once per week during active growth. Drought tolerant once established but consistent moisture produces the best roots. Reduce watering in winter when dormant.
- Good companions
- Potato
- Keep away from
- Other brassicas (shares diseases)
Tropical Growing Tips for Horseradish
Recommended Varieties
- Not recommended for tropical zones
Key Challenges
- No winter dormancy period
- Roots lack pungency without cold
- May not survive wet season
Pro Tips
- Horseradish is not suited to tropical zones. It needs cold to trigger root starch storage
- Consider Japanese horseradish (wasabi) or galangal as tropical alternatives
- If growing purely for leaves, it may survive but root quality will be poor
Pests and problems for Horseradish in Tropical
Harvesting Horseradish
When ready: Harvest after the first frosts of autumn/winter, or at least 16-24 weeks after planting. Roots should be at least 30cm long and 3-5cm diameter at the crown. Leaves may have died back partially in cold climates.
How to harvest: Dig deeply alongside the root with a garden fork. Roots can go 60cm+ deep. Lever out carefully. Any root fragment left in soil WILL regrow, so be thorough if you want to contain the plant. Snap off side roots for replanting or discard in bin (not compost).
Storing and preserving horseradish
How to keep it
- Freezing (Best for Long-Term Pungency). Peel and cut roots into chunks. Freeze on tray then bag. Grate from frozen as needed. Frozen horseradish grates easily and maintains pungency much better than refrigerated prepared sauce. Keeps: 6-12 months frozen.
- Root Cellar / Sand Storage. Unwashed roots stored in damp sand in a cool (1-4C), dark, humid place. Or wrap in damp towel in plastic bag in fridge crisper. Keeps: 3-6 months in root cellar, 2-3 months in fridge.
- Dehydrating (Horseradish Powder). Peel and grate or slice very thinly. Dry at 55C for 8-12 hours until completely crisp. Grind to powder. Warning: dehydrating horseradish produces extremely pungent fumes. Do outdoors or in very well-ventilated space. Keeps: 12 months in airtight container.
- Prepared Horseradish (Vinegar-Preserved). Peel roots and cut into chunks. Grate finely in food processor (OUTDOORS or in well-ventilated area, fumes are extremely pungent). Immediately mix grated root with white vinegar (1/4 cup per cup of root) and 1/2 tsp salt. The timing of vinegar addition is critical: add immediately for milder sauce, wait 3 minutes for maximum heat. Pack into clean jars. Keeps: 4-6 weeks refrigerated (pungency fades over time).
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 Horseradish
When do you plant horseradish in Australia?
It depends on your climate zone, not the calendar month alone. Planting months by zone:
- Tropical (Cairns): not recommended
- Subtropical (Brisbane): Apr, Aug to Oct
- Warm Temperate (Sydney): Mar to Apr, Aug to Oct
- Cool Temperate (Melbourne): Mar to Apr, Jul to Oct
- Cold / Highland (Canberra): May to Sep
- Arid / Semi-Arid (Alice Springs): Apr to Aug
- Mediterranean (Perth): Jul to Sep
When should I plant Horseradish in Cairns?
Horseradish needs cold winters to make pungent roots and does not suit the tropics. Grow galangal or ginger for heat instead.
What soil temperature do Horseradish need?
Horseradish germinate best when soil temperature is between 10°C and 25°C.
How do I know when Horseradish are ready to harvest?
Harvest after the first frosts of autumn/winter, or at least 16-24 weeks after planting. Roots should be at least 30cm long and 3-5cm diameter at the crown. Leaves may have died back partially in cold climates.
What are the best Horseradish varieties for Cairns?
Recommended varieties for the Tropical zone include: Not recommended for tropical zones.
What grows well with Horseradish?
Good companion plants for Horseradish include: Potato.
Are horseradish salt tolerant?
Only a little. Horseradish 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.