🌱 Watercress

Sowing window (UK)	March to September
Minimum soil temperature	5°C at seed depth
Spacing	10 cm apart
Days to germination	10 days
Days to harvest	40 days
Sowing method	Direct sow outdoors
Frost hardy	Yes
Sun	partial-shade
Watering	high
Plant family	Brassicaceae

When should I sow Watercress in the UK?

In the UK, sow Watercress from March to September. It is normally sown direct outdoors. Wait until the soil has reached 5°C at seed depth rather than going by the calendar - watercress will sit and rot in cold ground.

What soil temperature does Watercress need to germinate?

Watercress needs a minimum soil temperature of 5°C at seed depth to germinate reliably. Below that, germination is slow and patchy, and seed is more likely to rot than sprout. Measure at around 5cm down, in the morning, rather than trusting air temperature.

How deep and how far apart should I sow Watercress?

For Watercress, space plants 10cm apart.

How long does Watercress take to grow?

Watercress takes roughly 40 days from sowing to harvest. Seed usually germinates in about 10 days.

Is Watercress frost hardy?

Yes. Watercress is frost hardy and will stand through UK frosts, so it can be left out over winter in most of the country.

Sowing data cross-checked against RHS growing guides and UK seed-merchant catalogues. Soil temperatures are the minimum for reliable germination, measured at seed depth.