With a peppery and pungent flavor, this ancient plant is popular around the world for its nutritional and medicinal value. High in vitamins A, C, and K, as well as providing potassium and calcium, watercress has been studied for its antioxidant properties. At home along streams and lakes, watercress can also be grown in moist, partly shady gardens and indoors in containers.
• Botanical Name: Nasturtium officinale
• Family: Brassicaceae
• Native: Uncertain
• Hardiness: Perennial in USDA zones 6–9, otherwise grown as an annual
• Plant Dimensions: 10"–14" tall
• Variety Information: Small, roundish, light green leaves with a peppery, pungent flavor and scent.
• Exposure: Full sun to part shade
• Attributes: Good for Containers
• When to Sow Outside: 2 to 4 weeks before your average last frost date. Ideal soil temperature for germination is 50°–60°F.
• When to Start Inside: 4 to 6 weeks before your average last frost date. When growing indoors, keep continually moist.
• Days to Emerge: 5–15 days
• Seed Depth: ¼"
• Seed Spacing: 1"
• Row Spacing: 6"
• Thinning: When 1" tall, thin to 1 every 4"
• Harvesting: When plants are 4"–6" tall, clip sprigs off the top; the tips are the sweetest, most tender part of the plant. In mild climates, harvest during the cooler parts of the year.