In the cool greenhouse - minimum temperature to aim at, 45 Fahr. - successive batches can be brought on of chrysanthemums, winter-flowering begonias, perpetual carnations, etc. These can be followed by early Roman hyacinths and other Dutch bulbs. Summer-flowering heaths and kindred "American" plants will need keeping as cool as possible.
Where more heat is available, many early-flowering shrubs and roses may be forced, starting them slowly, however. Spiraea confusa, Thunbergias, Prunus sinensis, flore pleno, lilacs, deutzias, Azaleas, Philadelphus, and Viburnums can be treated in the same way; as also can such flowers as Solomon's seal, lily-of-the-valley, bleeding heart, and Astilbe japonica.