How far apart should I plant Watercress?

About 15 cm (6 in) apart, centre to centre. A mature plant spreads 30 cm–1 m (12 in–3.3 ft).

Does Watercress need full sun?

Full sun: at least 4 hours of direct sun a day.

How much water does Watercress need?

High water. Drought tolerance is none and waterlogging tolerance high.

How cold-hardy is Watercress?

It tolerates about -15 °C (5 °F) once established, roughly USDA zone 7.

When does Watercress flower?

From about May for 4–13 weeks (northern hemisphere; later in cold climates, earlier in warm ones).

Is Watercress poisonous to cats and dogs?

For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. Not poisonous. Do not eat cress gathered from water that grazes sheep or cattle: it can carry liver fluke.

What grows well with Watercress?

Traditional lore says rhubarb planted near brassicas helps against clubroot and pests; the evidence is weak and not confirmed by trials. Nasturtiums act as a trap crop for cabbage white butterflies and blackfly, drawing some pressure away from brassicas.

Watercress Nasturtium officinale

Watercress (Nasturtium officinale) is an evergreen perennial vegetable in the Brassicaceae family, native to Europe, western Asia and North Africa. It grows 10–50 cm (4–20 in) tall and 30 cm–1 m (12 in–3.3 ft) wide, wants full sun and high water, and is hardy to about -15 °C (5 °F). Space plants about 15 cm (6 in) apart.

Plan Watercress in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.

Watercress at a glance

Type	Perennial vegetable, evergreen
Family	Brassicaceae
Mature height	10–50 cm (4–20 in)
Mature spread	30 cm–1 m (12 in–3.3 ft)
Spacing	15 cm (6 in) centre to centre
Sun	Full sun, at least 4 h of direct sun a day
Water	High; drought tolerance none, waterlogging tolerance high
Soil pH	6.5–7.5
Cold hardiness	About -15 °C (5 °F) once established (roughly USDA zone 7)
Heat stress	Likely above about 28 °C (82 °F)
Flowering	from about May for 4–13 weeks (northern hemisphere; later in cold climates, earlier in warm ones)
Wind tolerance	Low
Pollinator value	Low
Edible	Yes: leaves and shoots
Native to	Europe, western Asia and North Africa
Common in gardens of	🇬🇧 United Kingdom, 🇫🇷 France, 🇺🇸 United States, 🇳🇱 Netherlands, 🇩🇪 Germany, 🇵🇹 Portugal, 🇳🇿 New Zealand, 🇯🇵 Japan, 🇨🇳 China

Is Watercress toxic?

People: not known to be toxic
Cats: not known to be toxic
Dogs: not known to be toxic

Not poisonous. Do not eat cress gathered from water that grazes sheep or cattle: it can carry liver fluke.

If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.

Companion planting: what to grow with Watercress

Good neighbours

good With Rhubarb: Traditional lore says rhubarb planted near brassicas helps against clubroot and pests; the evidence is weak and not confirmed by trials. Evidence D
good With Nasturtium: Nasturtiums act as a trap crop for cabbage white butterflies and blackfly, drawing some pressure away from brassicas. Evidence C

Questions about Watercress

How far apart should I plant Watercress?: About 15 cm (6 in) apart, centre to centre. A mature plant spreads 30 cm–1 m (12 in–3.3 ft).
Does Watercress need full sun?: Full sun: at least 4 hours of direct sun a day.
How much water does Watercress need?: High water. Drought tolerance is none and waterlogging tolerance high.
How cold-hardy is Watercress?: It tolerates about -15 °C (5 °F) once established, roughly USDA zone 7.
When does Watercress flower?: From about May for 4–13 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
Is Watercress poisonous to cats and dogs?: For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. Not poisonous. Do not eat cress gathered from water that grazes sheep or cattle: it can carry liver fluke.
What grows well with Watercress?: Traditional lore says rhubarb planted near brassicas helps against clubroot and pests; the evidence is weak and not confirmed by trials. Nasturtiums act as a trap crop for cabbage white butterflies and blackfly, drawing some pressure away from brassicas.

Sources and evidence

Evidence grade B (B: extension service or peer-reviewed).

Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
GRIN-Global Taxonomy, USDA ARS
RHS Find a Plant (plant profiles and growing guides), Royal Horticultural Society

Notes and assumptions

Grown commercially in beds of clean, flowing chalk-spring water (Hampshire and Dorset). In a garden: a pot standing in a tray of water changed daily, or a stream edge. Naturalised in streams on every continent.

Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.

Related plants

Broccoli Brassica oleracea var. italica
Cauliflower Brassica oleracea var. botrytis
Cabbage Brassica oleracea var. capitata
Kale Brassica oleracea var. sabellica
Radish Raphanus sativus
Bok choy Brassica rapa subsp. chinensis
Brussels sprout Brassica oleracea var. gemmifera
Kohlrabi Brassica oleracea var. gongylodes