Crocosmia is a genus of flowering perennial plants native to South Africa. They are widely cultivated as ornamentals in gardens all over the world in climates similar to that found in their native region and can also be grown indoors as decorative houseplants. A number of cultivars have been developed and are readily available through gardening supply stores, nurseries, and mail order catalogs. The best sources for Crocosmia are catalogs specializing in bulbs, as they usually have more cultivars and access to rarer species.
These plants grow from corms and once established, they can be difficult to eradicate. They put up long green sword-like leaves topped with sprays of trumpet-shaped flowers. The flowers are usually yellow, orange, or red, although cultivars of other colors have been developed including pale apricot shades. The foliage dies back in the fall, and returns again in the spring after the corms have successfully overwintered.
Known by common names like falling stars and coppertips, Crocosmia are bright, colorful, and very hardy. They grow well in United States Department of Agriculture zones six through nine and can often be encouraged to grow in cooler climates although it may be necessary to dig the corms up and allow them to overwinter indoors in climates where frost is heavy. These plants do best when massed in a clump and can be used for borders, backgrounds, and bed plantings.
Crocosmia needs rich, well-drained soil to thrive. If the soil is heavy, it can be worked with sand and organic material to break it up and provide nutrients for the growing corms. These iris relatives also prefer full sun and should not be allowed to dry out completely between waterings. Dead foliage can be cut back in the fall and fertilizer in the spring can jumpstart the plants to get them putting out a flush of new growth.
For growing indoors and in containers, loose potting mixes are recommended to give the corms room to grow. The soil should be moist, but not soggy, and fertilizing periodically is recommended to keep the plants healthy. Gardeners concerned about spreading corms, a legitimate concern in many areas because these plants can become invasive, may want to consider growing Crocosmia in containers to prevent the plant from taking over the garden. Container gardening also allows people to easily relocate their plants if needed, and can foil gophers and other pests who might otherwise damage the roots and corms.