Plants that complete their life cycle over two growing seasons.  In the first year, they produce roots, stems, and leaves; in the second year, they flower, set seed, and die. Biennials are excellent additions to native and natural gardens. Despite their short lives, they provide ecosystem services over three years: host plant foliage for caterpillars in year one, a profusion of flowers for pollinators in year two, and homes for stem-nesting insects in year three as their stems die and hollow out.