When to Plant Watercress in Perth, Mediterranean Guide

Sow now in Mediterranean Soil 15.6°C, best 8–15°C. Too warm for it.

Soil temperature is modelled from Open-Meteo forecast (Perth), not a live sensor.

What this month normally looks like in Mediterranean

In October the Mediterranean zone normally runs 22°C by day and 10°C overnight, with about 38 mm of rain over 6 or 7 wet days. The coldest October night on record across the zone was -0.2°C, so a late frost is not out of the question. Averages 1991 to 2026, 19 postcodes, SILO.

Jump to section
  1. Planting calendar
  2. How to grow
  3. Local tips and varieties
  4. Pests and problems
  5. Harvesting
  6. Other zones and related crops
  7. Common questions

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This Watercress guide is written for the Mediterranean zone, which takes in Perth, Adelaide and Bunbury. Somewhere else? Your postcode picks the right one.

Not your zone? Cairns Brisbane Sydney Melbourne Canberra Alice Springs

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

Planting window
Sep to Apr
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.

Watercress

Photo: Wikimedia Commons

Planting Calendar for Mediterranean

  • Jan D
  • Feb D
  • Mar D
  • Apr D
  • May -
  • Jun -
  • Jul -
  • Aug -
  • Sep D
  • Oct D
  • Nov D
  • Dec D

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 Mediterranean zone right now, Watercress included, plus which veg has jumped in price at the supermarket. Free, and you can stop it in one click.

How to Grow Watercress in Mediterranean 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.

Members see the exact salt threshold, how much harvest it loses as salt rises, and what to grow instead. See what members get

Mediterranean 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 Mediterranean

Members see each pest score and pest risk alerts for your area. See what members get

Browse the full pest library →

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).

Members see the price history and price alerts for watercress. See what members get

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

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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:

Can you grow watercress all year round in Perth?

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

When should I plant Watercress in Perth?

Derived from the temperate chart (Seed Collection). Keep it wet in summer and give it afternoon shade.

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 Perth?

Recommended varieties for the Mediterranean 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 Mediterranean zone, Perth is its reference city.