Nasturtium officinale Care Guide
Nasturtium officinale (watercress) is an edible aquatic leaf vegetable used in paludariums and stream biotopes, thriving in cool, well-oxygenated flowing water.
Overview
Nasturtium officinale, watercress, is an aquatic herb and leaf vegetable of the family Brassicaceae. It has hollow stems that float in water, pinnately compound leaves, and small white-and-green flower clusters, and can reach up to about 60 cm in length. It is one of the oldest known leaf vegetables consumed by humans.
Taxonomy
- Family: Brassicaceae
- Genus: Nasturtium
- Scientific name: Nasturtium officinale
- Order: Brassicales
Habitat
The species is native to Eurasia and is now cultivated across temperate regions worldwide. Clear, fast-flowing chalk streams are its primary natural habitat in the UK; it favours alkaline water and is well suited to flowing, cool conditions.
Tank requirements
- Water type: freshwater (emergent / stream)
- Temperature: 10-22 °C (50-72 °F)
- pH: 6.0-8.0
- GH: 4-18 °dGH
- Lighting: medium
- CO2 injection: not required
- Placement: background; height up to ~30 cm
Growth and propagation
Watercress is fast-growing and is best kept emergent in paludariums and stream-style biotopes with cool, well-oxygenated, flowing water. It is propagated easily from cuttings. Frequent trimming, roughly every two weeks, both harvests edible growth and keeps the planting tidy.
Uses
Leaves, stems and fruit are edible raw or cooked, and the plant is notably high in vitamins K and C. Its preference for clean, running water makes it a fitting choice for cool stream biotope displays.