Growing flowers from seeds is a cost-effective way to grow flowers. Annual, perennial and biennial flowers can be grown from seeds. For the best results, use fresh seeds that were stored in cool conditions. Sow annuals after the soil has warmed in the spring. Certain perennials, such as peonies and hellebores, need exposure to cold to break dormancy and germinate.
There are a variety of annual flowers that do well from seeds. Begonias bloom with yellow, pink, red or white flowers. Cosmos flowers bloom with yellow, red and orange flowers, according to the Aggie Horticulture Extension. Zinnia flowers are available in pink, yellow and white blossoms. Snapdragons will bloom again if the old blooms are removed. Periwinkle is a self-seeder and tolerates full sun to shade. Nasturtium grows rapidly and favors dry soil. Pansies favor partial to full sun. Marigolds are available in a variety of colors and sizes, while alyssum flowers bloom into midsummer. Calendula tolerate alkaline soil, and celosia are available in purple, rose, orange and yellow flowers. Strawflowers prefer sandy soil.
Perennial seeds should be sown 1/4 inch apart, according to "Taylor's Guides to Perennials" by Barbara W. Ellis. Asters favor full sun and their flowers are shaped like daisies. Clematis bloom from the spring to the fall. Shasta daisies, delphiniums, zebra mallow, linaria and papaver flower from seed after the second year. Anemone is available in both spring- and fall-blooming varieties. Carnations prefer dry soil. Poppies are available in different varieties and can tolerate both partial shade and full sun. Dahlias are available in several different colors and favor full sun. Viola is a large family of flowers that include violets, pansies and violas; these flowers bloom in different colors including purple, white and purple-blue.
In cold climates, sow hardy biennial seeds outdoors beginning in late spring until midsummer, recommends "The Encyclopedia of Gardening" by American Horticultural Society. Hollyhocks are available with maroon, pink, white and yellow flowers. Foxglove has trumpet-shaped flowers in white, yellow and pink. Dame's rocket blooms with purple flowers that become more fragrant at night. Forget-me-nots are blue and reseed themselves. Moth mullen also self-seeds and has white flowers. Sweet William and Siberian wallflower both tolerate alkaline soil. Biennial guara blooms during the summer with pink flowers. Canterbury bells have cup-and-saucer shaped flowers and can be sown anytime from the spring until the fall. Silver sage blooms with white flowers with pink or yellow edges.