A tropical plant that is showing up more and more in the Indiana garden is Agapanthus, commonly called African lily or lily of the Nile. Agapanthus has densely packed balls of blue, white or purple flowers atop tall stems. It makes an excellent cut flower.
Snowstorm, Bluestorm, Summer Skies and Storm Cloud have been on the market for a few years. A new one, Summer Sky, one of Hines Growers’ Bloomstastic line of plants sent to me to trial this summer, has beautiful green and white strap like foliage. The plants bloom for about a month to six weeks in early to mid summer.
In the Midwest, we usually grow agapanthus in pots, so it can be moved indoors in winter. Depending on the cultivar, however, agapanthus may be winter hardy in USDA Zone 6. Some have been planted in the ground at the Indianapolis Museum of Art, where they have over wintered for two years, says Irvin Etienne, horticulture display coordinator.
Joe Gray of Hines suggests moving the agapanthus indoors in fall and growing it as a houseplant in a sunny window, moving it back outdoors in spring. Allow the soil to dry out between waterings, he says.
If sunny window space is at a premium, agapanthus can be wintered over in a dormant state, either in the pot it was growing in or dug from the ground, leaving soil attached to the roots, says Etienne. Remove any foliage and stow the pots or dug plants in a cool, dry place where they won’t freeze or get too warm and grow.
Do not water or fertilize dormant plants until moving them to a sunny location in spring to start the growing process. Most other tropical bulb and rhizome plants can be treated the same way.
Why should we go to all this trouble?
“You want agapanthus for those blue flowers, which can be large and rise 3 feet into the air,” Etienne says.