Celosia is a small genus of ornamental plants related to amaranth. Over 60 species of celosia exist, but three types belonging to two genera are commonly grown as flowers. Celosia argentea includes crested and plumed celosia and Celosia spicata includes spiked celosia. All are grown as perennials in U.S. Department of Agriculture plant hardiness zones 10 to 12.
The plumosa group of Celosia argentea, or plumed celosia, has flower heads that look like brightly colored, fluffy feathers. The flower heads are composed of hundreds of tiny flowers. They can be 10 inches high on 12- to 16-inch-tall plants. Plants produce one central flower head that grows larger as the plant grows, along with smaller side shoots with smaller flowers. Some new varieties continue producing showy new flower heads all summer.
The flowers of crested celosia are dense and folded. Some are rounded and look like a brilliantly colored brain or coral, while others are narrow and look like a rooster's comb. Varieties range from dwarf types, 4 to 6 inches tall, to 3-foot plants with 18-inch flower heads. Flower colors include red, yellow, orange, gold and pink. They generally have a large central flower and the flower head may become so heavy that taller varieties need staking.
Spiked celosia, also known as wheat celosia, is shrubbier than other varieties and has numerous flower heads. The flower heads are flattened, narrow cones with the flowers arranged like wheat grain. The colors are more muted than the other celosia with red, pink and white varieties. Some grow only 18 inches tall, others 3 to 4 feet.
Growing and Using Celosia
Celosia grow easily from seed. They do not do well if the roots are disturbed, so if they are started indoors, they should be grown in a paper or peat pot that can be planted. Celosia will grow in almost any soil, but does best in fertile well-drained soil. Requiring full sun, the plants are somewhat drought tolerant, but should be watered in long periods of dry weather. Cut flowers can be used fresh or dried.