Most triploid cultivars grow from 12 to 18 inches high. In addition to combining qualities of the two different parental types, the triploids are sterile and incapable of producing viable seeds. Since none of the triploid plant's energy is directed to seed production, flowers are produced in profusion over a long period. Seeds are expensive and the germination rate is rather low. Mail order seed companies list many cultivars.
Dwarfs are excellent for edging walkways, flower beds and borders.
Tall cultivars are good for background use in beds and mixed borders. Taller growing cultivars can be planted in rows in the vegetable garden or a cutting garden for use as cut flowers in the home. Over fertilization and excessive soil moisture can result in too much foliage and not enough flowers. Plant the low and intermediate height cultivars 6 to 12 inches apart. Space the tall Africans 12 to 18 inches apart.