Great Yellow Cress
Rorippa amphibia

Family: Brassicaceae or Cruciferae

What it is like

Rorippa amphibia is a PERENNIAL growing to 1.2 m (4ft). See above for USDA hardiness. It is hardy to UK zone 6 and is not frost tender. It is in flower from June to August, and the seeds ripen from July to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, flies. The plant is self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very acid and very alkaline soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist or wet soil and can grow in water.

Height (m): 1.2

Where it is found

By ponds, ditches and streams, often in water, in acid or calcareous conditions.

Most of Europe, including Britain, to N. Africa and Siberia.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 3

Young leaves and stems - raw or cooked. A hot cress-like flavour, they go well as a flavouring in salads.

Medicine

Rating: 0

Other

Rating:

How it is grown

Prefers a fertile soil. Tolerates fairly low light levels. Plants grow in boggy soils or in shallow water, the submerged forms have finely divided bright green leaves. Plants seem to be extremely attractive to slugs. They can eat out all the new growth in spring and kill even large plants.

Propagating it: Seed - sow spring in a cold frame. Germination should take place within 2 weeks. Prick out the seedlings into individual pots when they are large enough to handle and plant them out in the summer. Make sure the pots are not allowed to dry out. Division in spring. Very easy, but protect the young divisions from slugs. Larger divisions can be planted out direct into their permanent positions. We have found that it is better to pot up the smaller divisions and grow them on in light shade in a cold frame until they are well established before planting them out in late spring or early summer. Cuttings succeed at almost any time in the growing season. Very easy, even a floating leaf will form adventitious roots.

Best place to grow: Pond; Bog Garden;

Habit: Perennial

Hardiness: 5-9

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist, wet, water

Things to keep in mind

Its other names

Local names

Synonyms

Nasturtium amphibia. Sisymbrium amphibia.