This section is from the book "The Florists' Manual", by William Scott. Also available from Amazon: The Florist's Manual.
Strong growing tropical annuals having feathery spikes of flowers and highly colored leaves. They are very suitable for the mixed border or for large subtropical beds. It is on account of the showy markings of the leaves that they are mostly grown. They should not be planted out till settled warm weather, with us the first part of June, but they grow very luxuriantly in the warm months. They require deep, rich soil to obtain the best results.
Sow the seed the latter part of March in pans in a warm house and transplant when large enough to handle into flats, placing them two or three inches apart. The moist heat of a hotbed suits them finely. If extra good plants are required they can be shifted from the flats singly into 3-inch pots, and nowhere will they do so well as in a hotbed.
A few of the handsomest are: Bi-color, foliage green and yellow; hypo-chondriacus, large spikes of crimson flowers; salicifolius, narrow drooping leaves, orange, carmine and bronze; sanguineus, blood red leaves; tricolor, a very handsome species with carmine and yellow leaves.