How to grow Watercress

Nasturtium officinale

🥕 Vegetable 🌿 Herb 🌱 Grown each year

Peppery, iron-rich leaves that grow happily in a pot standing in a tray of water — no stream needed.

At a glance: Sow mid March to mid May, harvest from late May.

When to sow, plant and harvest

JanFebMarAprMayJunJulAugSepOctNovDec

Sow indoors

Plant

Harvest

Timed for a typical UK garden (last frost mid-April). The app uses your own town's frost dates.

Light: Part shade · 6+ hours a day
Watering: Keep constantly wet — stand the pot in a tray of water and change it every day or two
Soil: Fertile, well-drained soil
Spacing: 15 cm
In pots: Grows well in containers
Feeding: A general feed before sowing or planting
Harvest: About 50 days from sowing
Hardiness: USDA zones 3–9
Difficulty: Easy

Mid March – mid May · 4 weeks before the last spring frost
Sow Seeds Indoors
Sow in modules or small pots of seed compost under cover. Surface-sow and keep the compost soaking wet.
5–10 days after “Sow Seeds Indoors” · Late March
Check Germination
Seedlings should appear in 5–10 days. If sown outdoors, thin to 15 cm apart when big enough to handle.
14–21 days after “Check Germination” · Early April – mid April
Pot On Seedlings
Move seedlings into 9 cm pots (or keep in modules) when they have their first true leaves.
Mid April · 4 days after the last spring frost
Harden Off
Stand plants outside by day for 7–10 days before planting out.
Late April – late May · 2 weeks after the last spring frost
Plant Out
Plant out 15 cm apart and water in well.
28–49 days after “Plant Out” · Late May – mid June
Start Harvesting
Cut stems 10 cm long; pinch out flower buds to keep leaves coming.
90–120 days after “Start Harvesting” · Late August – late September
Finish and Clear
Clear the remains to the compost heap once cropping ends.