Watercress Seeds – Nasturtium officinale
Nasturtium officinale • Brassicaceae • Native to Europe, W. Asia
Watercress Seeds grow into fast-growing, aquatic or semi-aquatic leafy plants with a peppery flavor. Ideal for edible gardens, containers, water features, and fresh salad harvests.
Seed Variety: Broadleaf Watercress Seeds
Quantity: 100 Seeds
Selected: Broadleaf Watercress Seeds / 100 Seeds
Germination depends on soil, temperature, moisture, and care. See our return policy for details.
At a glance
Watercress grown in or near natural waterways can absorb contaminants and harbor liver fluke parasites, so always grow it in clean, controlled water sources and wash it thoroughly before eating.
Botanical profile
Meet the Watercress – Nasturtium officinale
Step-by-step planting
Growing watercress from seed is straightforward once you understand its love of moisture and cool temperatures, but conditions in your garden will shape how the process unfolds.
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1
Choose Your Site or Container
Watercress container growing works well in wide, shallow trays or pots without drainage holes, kept filled with an inch or two of clean water, or plant directly into consistently boggy soil near a water source for a more naturalistic aquatic herb garden.
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2
Prepare the Growing Medium
Use a fine-textured, nutrient-rich compost mixed with sand or aquatic planting media, aiming for a soil pH between 6.5 and 7.5 where watercress absorbs nutrients most efficiently.
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3
Sow the Seeds
Scatter watercress seeds thinly across the surface of moist growing media without burying them, as they need light to germinate, then press them gently into contact with the soil using your fingertips.
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4
Keep the Surface Consistently Moist
Mist the surface twice daily or set containers in a shallow tray of water to maintain the constant moisture that watercress germination depends on, never letting the soil surface dry out between waterings.
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5
Germination and Thinning
Once seedlings are an inch or two tall, thin them to about three to four inches apart so each plant has room to spread and air can circulate between stems.
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6
Maintain Water and Feed Lightly
Top up container water regularly and apply a diluted liquid fertilizer every two to three weeks during active growth, since watercress is a heavy feeder in confined spaces.
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7
Harvest Often
Begin harvesting when stems reach four to six inches by snipping just above a leaf node, which encourages bushy regrowth and delays the plant from bolting to seed.
Year-round care
Spring
- Sow after last frost
- prepare soil with compost
Summer
- Water regularly
- feed monthly
Fall
- Harvest before frost
- store well
Winter
- Rest
- store seeds cool and dry
Full specifications
Shipping
- Orders are delivered within 8 to 16 business days.
- All orders include tracking.
- Free shipping on all orders.
- Seeds are packed in moisture-resistant, resealable foil packets.
Germination
Germination rates vary depending on climate, soil conditions, and care. Seeds perform best when planted in the right season at the correct temperature, with consistent moisture and adequate light. We take quality seriously and each batch is tested before packaging. If you have concerns about your seeds, reach out and we will do our best to help.
Frequently asked
Questions about Watercress Seeds – Nasturtium officinale
How long does watercress take to germinate?
Under good conditions with soil temperatures between 55 and 65 degrees Fahrenheit and consistent moisture, watercress seeds often sprout within 7 to 14 days. That said, watercress germination is sensitive to temperature swings, uneven watering, and seed depth, so your results may be faster or slower depending on your specific setup. If nothing has appeared after three weeks, check that the surface is staying moist and that seeds have not been buried or washed away.
Can watercress grow in containers?
Watercress container growing is one of the most practical ways to cultivate this plant at home, especially if you lack a stream or pond. Use a wide, shallow container without drainage holes, or place a standard pot inside a slightly larger tray kept filled with an inch of water at all times. A sunny windowsill or shaded patio spot works well, and you can grow a continuous supply by succession sowing every few weeks.
Is watercress safe for pets?
Watercress is generally considered non-toxic to dogs and cats, and small amounts are unlikely to cause harm. However, feeding large quantities to pets is not advised, as the peppery compounds that make it appealing to humans can irritate a sensitive stomach. If your pet has a history of digestive issues or kidney problems, check with your vet before letting them graze on it.
What soil pH does watercress prefer?
Watercress grows well in a slightly alkaline to neutral pH range, ideally between 6.5 and 7.5. Outside of this range, nutrient uptake can become less efficient, and plants may look pale or grow slowly even with adequate water. If you are unsure of your soil or water pH, inexpensive test strips are easy to find at garden centers and worth using before you start.
When should I harvest watercress?
Harvest once stems are four to six inches long, which typically happens within three to five weeks of germination under good growing conditions. Cut stems just above a leaf node rather than pulling from the base, which encourages the plant to keep producing. Harvest frequently, especially as temperatures warm, because letting stems flower and set seed causes the flavor to turn bitter.
Does watercress need full sun?
Watercress grows well in partial shade to full sun, and in warmer climates it actually prefers a spot with afternoon shade to prevent bolting and bitterness. In cool spring and fall conditions, a full sun position is fine and will encourage faster, more vigorous growth. If you are growing indoors, a bright windowsill with four to six hours of direct light is usually sufficient.
Is watercress invasive in the US?
Nasturtium officinale is listed as invasive or naturalized in many parts of the United States, particularly in the Pacific Northwest and other regions with cool streams and waterways. It spreads aggressively through stem fragments carried by water currents, and once established in a natural waterway it can crowd out native aquatic plants. To be a responsible grower, keep your watercress in containers or enclosed garden beds rather than planting it directly into or near natural water sources.