Watercresses in Penrhosfeilw

Nasturtium officinale

Watercress
Watercress · Nasturtium officinale

Watercress is a hardy perennial leafy crop that grows best in shallow running water or very wet soil. In the UK it’s usually grown outdoors in a pond basket, streamside bed, or container kept constantly wet, and it gives the best leaves in cool weather.

20 cm · Partial Shade · High Water

Add to garden

Calibrated to Penrhosfeilw · last frost ≈ 30 Mar

Sow January to April, plant out March to April, harvest May to November. Frost risk November to March.
ActivityJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
SowYesYesYesYesNoNoNoNoNoNoNoNo
Plant outNoNoYesYesNoNoNoNoNoNoNoNo
HarvestNoNoNoNoYesYesYesYesYesYesYesNo

Growing guide

Step-by-step instructions for growing Watercress

  1. 01

    Sow Seeds

    28 Jan to 30 Apr every 3 weeks

    Sow seeds around 28th January - 30th April on the surface of very moist compost, 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.

  2. 02

    Thin Seedlings

    29 Mar to 5 Apr

    When seedlings are large enough to handle, from 29th March, thin them so the strongest plants have room to spread. Keep the soil wet at all times, because even brief drying checks growth.

  3. 03

    Transplant

    16 Mar to 27 Apr

    Move seedlings to their final spot around 16th March - 27th April, spacing them well apart in mud-like soil or a shallow run of water. Water in thoroughly straight after planting and keep the roots submerged or constantly wet.

  4. 04

    Feed Plants

    6 Apr to 29 Nov every 2 weeks

    From 6th April, give a very light liquid feed every 14 days if growth slows, but avoid strong feeding that makes the leaves coarse. Keep the bed weed-free and topped up with water.

  5. 05

    Harvest Leaves

    3 May to 29 Nov

    Start cutting from 3rd May when plants are well rooted and the shoots are leafy. Pick little and often through to 29th November, taking the outer stems first and leaving the centre to regrow.

Companion plants

Tap a plant to see why it works (or doesn't) with Watercress.

Good companions

Plants to avoid

Why companion planting matters

Companion planting can deter pests, improve pollination, and make better use of space. Some plants confuse pests or attract beneficial insects; others improve soil or offer shade to neighbours that need it.

Watercress guides by town

See how Watercress timing shifts in other towns with different frost dates.