It has gained popularity as an ornamental garden plant. There are about 300 species of plants in the genus Dianthus. It is a short-lived perennial or biennial that is sometimes cultivated annually.
Sweet William usually grows 12 to 24 inches tall with small flowers in dense, flattened clusters (3 to 5 inches wide). Wide varieties are commercially available, including double flower shapes and some dwarf plants (4 to 8 inches tall).
The flowers come in vibrant reds, pinks, whites, and two-tone hues, often with contrasting eyes and bearded petals lined on the inside. It blooms from late spring to early summer. The flowers can be fragrant, although most new varieties are odorless.
The medium green, lanceolate leaves are up to 4 inches long.