Gladiolus are as American as apple pie. Generations of gardeners, from Maine to California, have tucked these summer-blooming bulbs into their gardens in spring and been delighted by the gorgeous flower spikes that appear just a few months later. Buckets of long-stemmed glads are a late-summer tradition, and they can be found at almost any county fair or farmer’s market.
In fact, gladiolus are far more exotic than you may think. Most are native to Africa and other arid countries around the Mediterranean. Plant breeders didn’t begin working with gladiolus until the late 1800s, but they have had great success. Today’s glads are far showier than those that grow in the wild and the color options are simply incredible. No wonder floral designers, flower farmers, and home gardeners are finding new and creative ways to put glads front and center.
Gladiolus Basic Types and Variety Names
Gladiolus owe their botanical name to the Latin word gladius, which means sword. It’s an accurate description of the plant’s stiffly upright form and narrow, blade-like leaves. There are several different types of glads in cultivation. They vary in height as well as in flower form and size.
Grandiflora Hybrids: The gladiolus that grew in our grandmother’s and great-grandmother’s gardens were probably grandifloras. They have the classic orchid-like flower shape and come in an incredible range of colors, including pink, purple, red, yellow, green, white, and orange, plus many bi-colors. Flowers are 5 to 6” across. Grandifloras grow 3 to 4-feet tall and have 12 to 20 blossoms per stem. They are reliable winter hardy in zones 7 and warmer.
Dwarf Grandiflora Hybrids: These miniature gladioli produce 2 to 3-foot stalks and display 2-3” wide, open-faced flowers. Being smaller in size and often not needing staking, dwarf glads are a popular choice for flower gardens, containers, and cutting gardens. “Butterfly glads” are sometimes classified as dwarf hybrids and sometimes as Primulinus hybrids. They feature throat blotches in contrasting colors. “Glamini” glads also fall into this category. As with the grandiflora hybrids, these corms are reliably winter hardy in zones 7 and warmer.
Gladiolus Nanus Hybrids: These flowers resemble grandifloras but are 1/2 to 2/3 the size and there are usually just 6-7 flowers per stem. The color range is more limited, with most varieties having blossoms that are red, white, pink, or rose (plus bicolors). At just 18 to 24 inches tall, these smaller and less formal glads work well in pots and are a lively addition to a mixed flowerbed. Gladiolus nanus bloom in early to midsummer and will usually survive the winter in zones 5 and warmer.
Gladiolus communis var. byzantinus: Byzantine glads have naturalized in many southern gardens. Each arching 2-foot stem displays about a dozen tubular, bright magenta flowers. Bloom time is early to midsummer. The corms are hardy in zone 7 and warmer.
Dalenii Hybrids (formerly Gladiolus primulinus): These glads have slender, 2 to 3-foot stems with flowers that are about half the size of grandiflora types. The blossoms appear to be “hooded” rather than fully open. Dalenii hybrids are hardier than grandifloras and will survive the winter in zone 6 and warmer.
Gladiolus callianthus and Gladiolus murielae: Commonly known as peacock orchids, these gladiolus relatives are now classified as Acidanthera murielae.
Learn more about gladiolus from the National Garden Bureau.
