In cool climates celosias are grown as annuals. Celosia argentea is probably native to Asia, and there are two different groups of cultivars. One group has plume-type flower heads and the other group, the cristatas or cockscombs, has wavy crests that are often described as looking like a brain. Another common name is Chinese woolflower, which describes the chenille type texture of the blooms.
Both types, the plumes and the cockscombs have been cultivated in a range of colors, but are usually red, yellow or pink/orange, in both tall and dwarf strains. Both are available at garden centers each spring, usually in packs of annual bedding plants in mixed colors. The genus, however, contains a variety of species of erect annuals, perennials and shrubs in the amaranthus family, though these are rarely available, so we are most likely only to grow the C.argentea species.
They are useful in the summer garden as they can withstand heat and like full sun, rich well-drained soil and constant moisture. They grow well from seed and frequently self sow. The flower heads contain a myriad of small black seeds (a bit like poppy seeds), and they can be collected in late summer.
The tall (three foot) plants produce flower heads that grow on very wide sturdy stems and can be hung upside down to air dry, and they retain their rich colors for winter bouquets.
Children especially seem to enjoy growing the cockscomb types, and sometimes the flower heads can be left on the plant until the heads are huge and quite amazing to see and show to the neighbors.
Celosias make good companions for other strong colored annuals in the cutting garden, such as zinnias and marigolds. The dwarf varieties are often used as edging plants, as they thrive in the heat reflected from concrete or stone edging.