When to plant Watercress in London

Nasturtium officinale

A hardy perennial leafy vegetable for containers of compost kept constantly wet with clean water. It grows best in cool conditions and light shade. Keep home-grown edible watercress separate from natural ponds and streams where water may be contaminated by livestock or wildlife.

20 cm · Partial Shade · High Water

Add to garden

Calibrated to London · last frost ≈ 4 Apr

Sow indoors February to April, plant out April to June, harvest April to November. Frost risk November to April.
Activity	January	February	March	April	May	June	July	August	September	October	November	December
Sow indoors	No	Yes	Yes	Yes	No	No	No	No	No	No	No	No
Plant out	No	No	No	Yes	Yes	Yes	No	No	No	No	No	No
Harvest	No	No	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No

Growing guide

What to do through the growing season

01
Sow Seeds
28 Feb to 11 Apr Optional · repeat every 3 weeks
Sow seeds around 28th February - 11th April on the surface of moist compost in small pots or modules, then press them in lightly rather than burying them. Keep the compost constantly damp while they germinate, and sow a fresh batch every 21 days for a steady supply.
02
Thin Seedlings
28 Mar to 16 May Dates as each sowing reaches this stage
When seedlings are large enough to handle, from 28th March, thin them so the strongest plants have room to spread. Keep the soil wet at all times, because even brief drying checks growth.
03
Transplant
4 Apr to 6 Jun
Move seedlings to their final container around 4th April - 6th June, spacing them apart in wet compost standing in shallow clean water. Water in thoroughly, keep the compost constantly wet, and refresh the standing water regularly. Do not use untreated water from streams or livestock ponds for edible leaves.
04
Feed Plants
4 Apr to 10 Nov Dates as each sowing reaches this stage Optional · repeat every 2 weeks
From 4th April, give a very light liquid feed every 14 days only if growth slows. Avoid strong feeding that makes leaves coarse, remove weeds promptly, and keep the container topped up with clean water.
05
Harvest Leaves
18 Apr to 21 Nov Dates as each sowing reaches this stage
Start cutting from 18th April when plants are well rooted and the shoots are leafy. Pick little and often through to 21st November, taking the outer stems first and leaving the centre to regrow.