50 Fresh Herb Seeds Caraway Caraway is categorized as a biennial flowering herb, which establishes itself quickly, within the first growing season. The plants then wilt on the surface, when the first frost arrives. Each plant will then later return the following year, from deeply established roots, growing on the surface to produce its flowers and seed. Caraway seeds can be collected from the dried blooms, a few short weeks after the flowers have withered and dried. Type: Herb. Season: Biennial. Heirloom: Yes. Color: White. Height: 18" - 24" Tall. Width: 18" to 20" Spread. Harvest: 400 Days For Seed. Uses: Culinary / Medicinal. Environment: Full Sun.