Annual plants and flowers are those that live their entire life (germination, seeding, growth and death) in a single year, technically speaking. Many horticulturists, however, call "annuals" those plants that will flower their first year from seed. Annual gardens can be effective for container gardening or for borders, providing a colorful splash in your landscaping.
Marigold, or Tagetes spp., is from the Asteraceae/Compositae, or aster/daisy family. It is a fast-growing beginner plant with hundreds of different varieties. Marigolds exist in three categories: the French, the triploid and the African (or American). French marigolds get 6 to 12 inches tall and produce 2-inch flowers. The triploid marigolds are hybrids between French and African, with 3-inch flowers. African marigolds can get to 3 feet tall and have a short bloom time and larger flowers than the rest. Marigolds need full sun and can adapt to the soil they are grown in. They propagate via seed.
Larkspur, or Consolida ajacis, is from the Ranunculaceae, or buttercup, family. Larkspur grows in about 40 different species, all of which are annuals. This beginner plant will attract hummingbirds. Larkspur will reach 2 to 3 feet in height and has flower in hues of blue, pink, lilac and white. Consolida ajacis is grown in full sun conditions and will propagate by self-sowing or by seeds planted in the early spring or fall. Its leaves and flowers, if eaten, can cause stomach problems and the leaves can cause contact dermatitis.
Sunflower, or Helianthus annuus, also is from the Asteraceae/Compositae, or aster/daisy family. These flowers will attract birds and butterflies into the garden because of their tasty seedheads. The majority of the species will get 8 to 15 feet tall with 8- to 12-inch flower heads. Sunflowers are grown in full sun with a neutral to slight alkaline soil that drains well. Propagate this flower through seed sown after the last frost. These seedheads can release volumes of tasty, edible sunflower seeds. Some people can be allergic to the foliage of a sunflower and develop contact dermatitis.