How to Grow and Care for Watercress

Watercress is a water-loving perennial herb known for its peppery flavor, often found growing along stream banks. It thrives in moist, organically rich soils and can be grown in garden water features or containers. Varieties like garden cress and upland cress offer unique traits. Despite its need for constant moisture, watercress is relatively easy to grow and care for.

• Common Names: Garden Cress, Curly Cress, Peppergrass
• Scientific Name: Nasturtium officinale
• Plant Type: Perennial, herb
• Plant Height: 6-10 inches
• Growing Difficulty: Easy
• Growing Time: 3-4 weeks
• Temperature: 60-70°F
• Hardiness Zone: 3-11 (Find your hardiness zone here)
• Sunlight: Full Sun to Partial Sun
• Soil pH: 6.5-7.5
• Watering Frequency: Keep the soil moist
• Plant Spacing: Space plants 6-8 inches apart

Different Methods to Grow Watercress

Growing in a Water Feature

Watercress thrives in water features like ponds or streams, mimicking its natural habitat. Plant it along the edges where the soil remains saturated.

• Pros: Mimics natural conditions, potentially less maintenance if the water feature is self-sustaining.
• Cons: Requires a suitable water feature, may not be feasible for all gardeners.

Growing in a Container

Use a pot with large drainage holes and a soilless potting mix. Place the pot in a saucer filled with water to keep the soil moist.

• Pros: Can be done in any garden, easy to control water levels, suitable for small spaces.
• Cons: Requires regular water changes, may need more frequent monitoring.

Growing Indoors

Place a container in a spot with at least four hours of sunlight daily. Ensure the soil remains moist at all times for optimal growth.

• Pros: Year-round growth, controlled environment.
• Cons: Limited sunlight, may need artificial lighting, requires constant moisture management.

Ideal Soil and Location Requirements

Watercress thrives in wet, organically rich soils with good water retention. It prefers full sun to partial shade and should be planted in consistently moist areas, such as near water features or in containers kept in saucers filled with water.

When to Plant Watercress

Watercress is best planted in early spring or fall, around three weeks before the last frost date. Seeds should be sown just below the soil surface, while transplants can be placed outdoors after the last frost. The cooler parts of the year enhance its flavor.

Growing Watercress Outdoors

Planting watercress in a garden is best done by ensuring the soil remains consistently wet and rich in organic matter. This method is effective because watercress thrives in moist conditions, making it easier to manage and maintain.

1. Choose the Right Location. Select a sunny spot with consistently wet soil. If possible, plant near a water feature like a stream or pond.
2. Prepare the Soil. Conduct a soil test to determine fertilizer needs. Work the recommended fertilizer into the top 6 inches of soil. Apply no more than 1 inch of well-composted organic matter per 100 square feet.
3. Plant Seeds. Sow seeds just below the soil surface, about ¼ inch deep, three weeks before the last frost date. Keep the soil wet for best germination.
4. Space the Plants. Space seeds 1 to 2 inches apart. Once seedlings emerge, thin them to 6 inches apart to allow for proper growth.
5. Water Regularly. Ensure the soil remains moist at all times. If growing in containers, place them in a bucket with 2 to 3 inches of water, changing the water once or twice a week.
6. Fertilize as Needed. Use a complete soluble fertilizer mixed with water at recommended rates every two to three weeks to prevent nutrient deficiencies.
7. Monitor Growth. Keep an eye on the plants, ensuring they receive at least four hours of sunlight daily and that the soil remains consistently moist.

Growing Watercress Indoors

Growing watercress indoors is entirely feasible with the right conditions. Here’s a step-by-step guide to help you grow watercress successfully at home.

1. Choose a Container. Use a pot at least six inches wide with large drainage holes.
2. Prepare the Potting Mix. Use a soilless potting mix containing perlite or vermiculite mixed with peat to increase water retention.
3. Plant the Seeds. Sow seeds just below the soil surface, about ¼ inch deep. Space seeds 1 to 2 inches apart.
4. Place the Pot. Position the container in a spot that gets at least four hours of sunlight per day.
5. Keep the Soil Moist. Place the pot in a saucer filled with water to keep the potting mix consistently moist. Change the water once or twice a week.
6. Maintain Temperature. Ensure the indoor temperature stays between 60 and 70°F for optimal growth.
7. Thin the Seedlings. Once seedlings emerge, thin them to 6 inches apart to allow for proper growth.
8. Fertilize Regularly. Apply an organic fertilizer, such as a kelp-based fertilizer, every two to three weeks if needed.
9. Monitor Growth. Check the plants regularly to ensure they are receiving enough light and moisture.

Watercress is not only a culinary delight but also a nutritional powerhouse. It is high in iron, calcium, folic acid, and rich in vitamins A and C. Interestingly, the flavor of watercress is at its peak during the cooler parts of the year, making it a perfect addition to winter salads.

Caring for Watercress

1. Keep the Soil Moist: Watercress thrives in wet conditions, so ensure the soil remains consistently moist. If growing in containers, place them in a saucer filled with water and change the water once or twice a week.
2. Monitor for Pests: Common pests include whiteflies, spider mites, and snails. Control whiteflies with soapy water, use natural predators for spider mites, and handpick or trap snails to keep them at bay.
3. Harvest Regularly: For the best flavor, harvest dime-sized dark green leaves before the plant flowers. Cut the plant back to about 4 inches tall and allow it to regrow. Watercress can be harvested year-round, and the leaves can be stored in the refrigerator for up to a week.
4. Fertilize as Needed: While watercress doesn't have high nutrient requirements, it may show deficiencies in phosphorus, potassium, or iron. Use a complete soluble fertilizer mixed with water every two to three weeks to address these issues.
5. Maintain Ideal Conditions: Ensure the plant receives at least four hours of sunlight daily and that the temperature stays between 60 and 70°F. Growth slows and the flavor becomes bitter if temperatures exceed 85°F.

Common Challenges With Watercress

Watercress is a resilient plant that is relatively easy to grow, provided it has plenty of moisture. It can be propagated by stem cuttings or seeds and thrives in various soil conditions as long as the soil remains saturated. Whether you choose to grow it in a garden water feature, a container, or even indoors, watercress adapts well and requires minimal maintenance. In my experience, once you get the watering right, the plant practically takes care of itself.

However, growing watercress does come with its challenges. The plant is susceptible to pests like whiteflies, spider mites, and snails, which can be managed with soapy water or natural predators. Another common issue is that watercress can become bitter in hot weather, so maintaining a cool environment is crucial. Additionally, keeping the area weed-free and ensuring the soil remains consistently moist are essential steps to avoid any setbacks. Despite these challenges, the rewards of fresh, peppery watercress make the effort worthwhile.

Safety of Watercress for Pets

Watercress is toxic to cats, dogs, and other pets. If you suspect your pet has ingested watercress, contact the ASPCA 24-hour hotline immediately for assistance.

Frequently Asked Questions

How often should I water watercress?

Watercress requires consistently moist soil. If growing in containers, place them in a saucer filled with water and change the water once or twice a week. For garden planting, ensure the soil remains wet at all times.

Can watercress grow in partial shade?

Yes, watercress can grow in partial shade, although it prefers full sun. When grown indoors, ensure the plant receives at least four hours of sunlight daily to thrive.

What are the common pests affecting watercress?

Common pests include whiteflies, spider mites, and snails. Control whiteflies with soapy water, use natural predators for spider mites, and handpick or trap snails to keep them at bay.

How do I propagate watercress?

Watercress can be easily propagated by stem cuttings or seeds. Sow seeds just below the soil surface, about ¼ inch deep, three weeks before the frost-free date. Keep the soil wet for best germination.