When to Plant Watercress 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 Watercress 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
- Mar to Sep
- Days to harvest
- 60 days
- Sun
- Full sun to part shade
- Water
- Regular
- Spacing
- 20 cm apart
Watercress is a peppery, hardy perennial salad leaf. It grows in wet soil or clean slow water, so a pot standing in a tray of water works at home.
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 D
- Apr D
- May D
- Jun D
- Jul D
- Aug D
- Sep D
- Oct -
- Nov -
- Dec -
S = Seed Tray T = Transplant D = Direct Sow
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How to Grow Watercress in Tropical Australia
- Soil
- Rich, moist soil kept constantly wet, or slow flowing clean water (Yates, Seed Collection).
- Salt
- Moderately sensitive. Copes with a little salt, but the harvest drops on salty bore water.
- Sunlight
- Full sun, 6 or more hours (Seed Collection). Yates says full sun or part shade. Succeed Heirlooms says shade if grown out of water.
- Spacing
- 20cm apart
- Watering
- Never let the soil dry out. Submerge pots in water to keep the soil moist (Yates).
- Good companions
- Chinese Water Chestnut
- 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 Watercress
Recommended Varieties
- Watercress (Nasturtium officinale)
Key Challenges
- Must never dry out
- Escapes into waterways
Pro Tips
- Grow in a pot standing in a tray of water
- Keep it away from creeks and drains
Pests and problems for Watercress in Tropical
Harvesting Watercress
When ready: Cut when plants are 10 to 15 cm tall (Yates).
How to harvest: Cut with scissors above ground level to encourage leafy growth (Yates).
What watercress costs in the shops right now, retailer by retailer, updated daily.
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 Watercress
When do you plant watercress in Australia?
It depends on your climate zone, not the calendar month alone. Planting months by zone:
- Tropical (Cairns): Mar to Sep
- Subtropical (Brisbane): Mar to May, Aug to Nov
- Warm Temperate (Sydney): Jan to Apr, Sep to Dec
- Cool Temperate (Melbourne): Jan to Apr, Sep to Dec
- Cold / Highland (Canberra): Jan to Feb, Oct to Dec
- Arid / Semi-Arid (Alice Springs): Mar to May, Sep to Nov
- Mediterranean (Perth): Jan to Apr, Sep to Dec
Can you grow watercress all year round in Cairns?
No. In the Tropical zone the planting months are Mar to Sep. Outside that window it either bolts, sulks or gets cut down by the weather.
When should I plant Watercress in Cairns?
Seed Collection lists March to September for the tropics and Succeed Heirlooms says any time of year. Keep the roots wet and give some shade in the build up heat.
What soil temperature do Watercress need?
Watercress germinate best when soil temperature is between 8°C and 15°C.
How do I know when Watercress are ready to harvest?
Cut when plants are 10 to 15 cm tall (Yates).
What are the best Watercress varieties for Cairns?
Recommended varieties for the Tropical zone include: Watercress (Nasturtium officinale).
What grows well with Watercress?
Good companion plants for Watercress include: Chinese Water Chestnut.
Are watercress salt tolerant?
Only a little. Watercress 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.