Nasturtium officinale 60 days. This cress is rich in vitamins and has a delicious, distinctive taste. Excellent with astringent fruits like oranges and grapefruit. Direct seed Watercress about ¼ inch deep, and about ½ inch apart. Thin to 4 inches and keep well watered. Grows best in full sunlight in very moist soil with a pH of 7. Approximately 1300 seeds per ¼ gram.