Grow this ancient, leafy plant known as Watercress, from freshly harvested Nasturtium officinale herb seeds. Watercress is an aquatic, or semi-aquatic plant that establishes itself in shallow bodies of water, such as ponds, streams and on the edge of rivers. They are known to grow to a mature height of roughly 18 to 24 inches tall, producing delicious green leaves. The leaves are rounded and the stems are hollow. Both are edible when harvested, and can be added to salads as a Spinach alternative. You might consider harvesting the leaves prior to flowering as they hold the best flavor when young.
Watercress is categorized as an annual herb / vegetable. Annuals will establish themselves in a single growing season, producing stems, leaves and flowers prior to wilting away during the first frost. The plants can produce seeds within the final weeks of Fall, allowing you to store them away for the following season.
Watercress carries the Latin name Nasturtium, which should not be confused with the flowering variety Tropaeolum, which is an entirely different species. Nasturtium and Watercress do however offer something in common. Both plants will produce a peppery like flavor when consumed.
Quick Facts
- Type: Herb
- Season: Annual
- Heirloom: Yes
- Color: Green Leaves
- Height: 18″ – 24″ Tall
- Width: 12″ Spread
- Harvest: 7 to 10 Days (Baby) 60 Days (Fully Grown)
- Uses: Culinary
- Environment: Partial Shade
Sowing The Seed
Watercress seeds can be established directly outdoors, or indoors as well. If started indoors, start in peat pots, or starter trays, 6 to 8 weeks prior to the last frost. Sow the seeds at a shallow depth of 1/16″ under topsoil. Mist the seeds and soil so that it is well saturated, continually watering them through their lifespan. Transplant or direct sow outdoors when the weather is warm and all danger of frost has passed.
Growing Conditions
Watercress is a cool weather crop / plant. They prefer an area that’s shaded from direct sunlight, with temperatures averaging around 55F to 75F. The soil, as explained prior, will need to be saturated fairly often, since the plants will naturally establish themselves in shallow streams and other small bodies of water. The soil should be fertile and rich in organic matter, but also well drained. Adding a light compost the any areas that consist of hard, compact soil, can increase your drainage.
Germination & Growth
Watercress will typically germinate within the first 7 to 10 days after sowing. The plants will grow to an average height of roughly 18 to 24 inches tall, but are best harvested when young. Each plant can be spaced about 6 inches apart from one another. Enjoy the delicious green leaves and hollow stems in salads, as a Spinach alternative.