ZINNIA  , in

botany, a genus of the natural order Compositae, containing about a dozen species of half-hardy annual or perennial herbs or undershrubs, natives of the southern United States and Mexico . The numerous single and double garden forms are mostly derived from Zinnia elegans, and grow about 2 ft. high, producing flowers of various colours, the double ones being about the size of asters, and very handsome . The colours include white, yellow, orange, scarlet, crimson and purple . Zinnias do best in a rich deep loamy soil, in a sunny position . They should be sown on a gentle hotbed at the end of March or in April and planted out early in June .