Vegetables like spinach, fennel, and lettuce are all mostly biennial plants. Find your favorite flower seeds and plants… Over the course of the second year, the plant will flower, then produce seeds before it dies. Biennial Flower Seeds These types of flowers have a two-year life cycle. Our annual flowers are available in both seeds and plants from the most trusted name in home gardening, Burpee. In the first year, biennials grow leaves, stems, and roots before going dormant for the winter. The plants … Harris Seeds has been a leading purveyor of the highest quality flower seeds since 1879. We carry an extensive selection of annual flower seeds and plants, perennial flower seeds, bedding plants and cut flower seed varieties. You can sow the seeds directly in your garden a few weeks before your final frost date, or start them indoors roughly six weeks before your projected last frost. These flowers have a lovely sweet fragrance and bloom from around April to June. Each lot of flower seeds that arrives at Harris Seeds is routinely tested for quality seed … a variety of fresh blooms. Annual Flowers - Seeds & Plants.