Watercress

Watercress (Nasturtium officinale) is an aquatic leafy green in the cabbage family, native to southern Europe and widely valued for its peppery, mineral-rich flavour. It thrives in consistently moist to waterlogged, lime-rich conditions in partial shade. The plant is exceptionally rich in vitamins A, C, and D. In Nordic gardens it is grown as an annual, either indoors like ordinary cress or outdoors in a cool, shaded, and reliably wet spot.

Growing

Sow seeds 0.5 cm deep indoors once nights stay reliably above 2 °C, or start indoors 4 weeks before transplanting outdoors. Seeds are light-sensitive germinators — keep trays evenly lit and consistently moist. Expect germination in 5–10 days. Space plants 10 cm apart in rows 10 cm apart. Outdoors, choose a shaded position with permanently damp or waterlogged, calcium-rich soil; standing water is ideal. Can also be direct-sown once frost risk has passed.

Care

Never allow the growing medium to dry out — consistent moisture is the single most critical requirement. If grown in containers, stand pots in a tray of water. Feed lightly with a balanced liquid fertiliser every two to three weeks. Remove any flower spikes promptly to extend the harvest period and keep flavour mild. No staking required.

Harvest

Begin harvesting leafy shoot tips once plants are 10–15 cm tall. Cut stems just above a node to encourage regrowth — watercress is a cut-and-come-again crop. Harvest in cool conditions: flavour is milder and shelf life significantly better when temperatures are low. Avoid harvesting once plants bolt, as leaves become bitter.

In the kitchen

Use fresh watercress raw in salads, sandwiches, and wraps where its peppery bite contrasts well with creamy or mild ingredients. Blend into soups — classic watercress soup is finished with cream or crème fraîche. Toss briefly into stir-fries or wilt over pasta at the last moment to preserve nutrients and colour.

Storing

Refrigerate unwashed stems standing upright in a glass of cold water, loosely covered with a plastic bag; keeps 3–5 days. Alternatively, wrap in damp paper and store in an airtight container in the fridge for up to 3 days. Watercress does not freeze well raw; blanched briefly it can be frozen for use in soups only.