Gladiolus, also known as sword lily, a perennial bulbous flower that belongs to the Iradaceae family, produces tall spikes with multiple, large blossoms. It can add height and color to any flower bedding or arrangements. Its showy blossoms come in various hues. According to University of Arizona, gladioli (plural) come in four types--winter blooming species and hybrids, summer blooming species, nanus or butterfly hybrids and modern summer blooming hybrids.
Winter Blooming Species and Hybrids
Winter blooming gladioli are smaller in comparison to the popular grandiflora hybrids. Gladiolus tristis, also known as ever- flowering gladiolus, is a winter blooming gladioli that originated from Africa. A monocot, G. tristis grows up to 2 feet tall, with leaves measuring up to 18 inches long. Its strongly fragrant flowers are white or light yellow, measuring up to 2.7 inches long and appearing on small, slender stalks. Typically, G. tristis have four to six buds per spike that bloom with intensely fragrant smell and can cross-pollinate with other species. Watering frequently during active growth will prevent G. tristis from going dormant; drought can stress and prevent flowering. G. caeruleus, G. carneus, G. huttonii, G. watsonius and G. trichonemifolius are some examples of other winter blooming gladioli.
Summer Blooming Species
An example of summer-blooming African species is Gladiolus dalenii, the main hybridizer of many summer blooming gladioli. G. dalenii grows up to 15.7 high and 1.4 inches in diameter. Leaf blades measure up to 3.9 inches long and produce foliage leaves after flowering on separate shoots. Approximately 5 to 12 flowered spikes appear during the blooming period. Flowers have yellow markings on the three lower tepal’s lower half or yellow to greenish with red to brown streaks on the upper tepals. G. dalenii prefers moist habitats, but can also show up in dry habitats that have shorter wet seasons. Other examples of summer blooming gladioli species are G. cruentus, G. oppositiflorus, G. papilio and G. saundersii.
Also known as butterfly gladioli or winter-hardy gladioli, nanus hybrids are popular commercial gladioli commonly sold in catalogs and garden centers. These gladioli are hardy to USDA Hardiness Zone 4 after overwintering in the ground. Nanus hybrids resulted from cross-breeding the summer and winter blooming species together. They are disease-resistant.
In contrast to the blotch pattern in modern summer blooming gladioli hybrids, nanus hybrids come in various colors ranging from white, pink, salmon and red with conspicuous darts of color on the upper petals. The color of the flower is in strong contrast with the rest of the plant and tends to look like a butterfly, hence, the name Butterfly Glads. About 12 buds appear on each spike. Examples of nanus hybrids are G. colvillei, G. nanus and G. hybrid.
Modern Summer Blooming Hybrids
Compared to the summer blooming species gladioli, modern blooming hybrids or Grandiflora are larger in flower and spike size. They can produce up to 40 buds. A stalk can hold up to 10 or more 5.5 inches wide open flowers. Modern summer blooming hybrid gladioli have flowers in various colors, such as pure white to almost jet black, and come with heavily textured flowers and ruffled petals. The most common colors are pink, salmon, reds, golden yellow and purple.
Summer and winter blooming species, including G. cardinalis, G. cruentes, G. oppositiflorus, G. papilio, and G. saundersii, lead to the creation of the modern Grandiflora hybrids.