Byzantine gladiolus or sword liliy (Gladiolus communis subspecies byzantinus) is an old fashioned favorite that has been growing in Southern gardens for hundreds of years. A true perennial, this survivor is commonly found in old cemeteries, abandoned home sites, and ditch banks. Native to the Mediterranean, these heirloom bulbs have adapted to our warm Southern climates and are hardy to at least USDA planting zone 6.
The first published mention of this beauty was in 1629 by John Parkinson. By 1820, the corms (the underground storage structure) were first advertised for sale in a nursery catalog in Flushing, New York. In 1993, sword lilies were awarded the prestigious Award of Garden Merit by the Royal Horticulture Society and were also named the 2006 Heirloom Bulb of the Year.
The corms are smaller than those of modern gladioli and are planted in the fall. Compared to modern gladioli, sword lilies have smaller, elegant, magenta flowers that are more orchid-like in appearance and bloom in late May to mid-June. The plants are self-supporting at two feet tall; therefore, they seldom need staking. Preferring full sun, sword lilies will grow in part shade but require well drained soil. After flowering, do not cut the foliage back, but allow it to senesce (turn yellow) and dry before removing the leaves, as this allows the corm to build up the food storage supply for the next year. They are deer and rabbit resistant, so are an excellent choice for gardens that have a lot of critter pressure.
Many years ago, I rescued a clump of sword lilies from the ruins of my great-grandmother’s garden. My clump has naturalized, and I’ve been able to divide and transplant these wonderful heirloom plants around my landscape. For more information on growing bulbs, see HGIC 1156, Summer-and Fall-Flowering Bulbs.