Winter hardy to USDA Zones 10-11. In other zones, grow as garden annuals or in pots that can be overwintered indoors or as houseplants. Grow in moist, organically rich, loose soils in part shade. Tolerates full shade. Some recently developed cultivars tolerate full sun. Soils must not be allowed to dry out. Remove flower spikes as they appear. Pinch plant stem tips to keep plants compact and to promote bushiness. Seed cultivars can be started indoors from seed 8-12 weeks before last frost date. Inexpensive starter plants (in small pots or flats) can be purchased from most nurseries in spring for beds and containers. Containers may be brought inside in fall before frost for overwintering. Similarly, favorite plants may be dug and potted in fall for overwintering as houseplants. Cuttings from favorite plants (easily rooted in a glass of water or in clean potting soil) can also be taken in fall for overwintering
