Common Name: gladiolus
Type: Bulb
Family: Iridaceae
Zone: 7 to 10
Height: 1.50 to 6.00 feet
Spread: 1.00 to 2.00 feet
Bloom Time: August to September
Bloom Description: White, cream, yellow, orange, red, pink, green lavender & purple
Sun: Full sun
Water: Medium
Maintenance: Medium
Suggested Use: Annual
Flower: Showy, Fragrant
Culture
Best grown in humusy, medium wet, well-drained soils in full sun. Adapts to a wide range of soils except heavy clay. Site plants in locations protected from strong winds. Although corms may be left in the ground year round in USDA Zones 7-10, it is generally believed that plants in these areas will flower best if corms are dug annually there as well. Corms may be started indoors in early spring (for earlier bloom) or planted directly in the ground after last frost date. Plant at two week intervals until June to extend the bloom time. Plant corms 4-6” deep and 5-6” apart. Provide consistent moisture during the growing season, especially during dry summer periods, and do not allow soils to dry out. After bloom, reduce watering. After foliage yellows and before the first significant fall frost, dig up corms, cut off stems and leaves, separate cormels (small corms at the base), dry corms and cormels, discard any diseased or damaged corms and store remaining ones for winter in a dry medium in a cool, frost-free location. If fungal diseases have been a problem, consider dusting corms with a fungicide immediately prior to storage. Corms may also be planted in containers with corms stored for winter in the same manner as if they were planted in the ground.
Noteworthy Characteristics
Gladiolus is a genus of about 180 species of corm-bearing plants from mainly South Africa but also found in the Mediterranean, Arabian Peninsula, northwestern Africa and eastern Africa. The wide range of hybrids produce some of the showiest of summer garden flowers. They are also a mainstay in the florist trade. Gladiolus produce sword-shaped, medium green leaves in upright fans and funnel-shaped flowers on slender scapes from summer into fall. There is an extensive range of flower colors available, including shades of white, cream, yellow, orange, red, pink, lavender, purple and green. Most of the gladiolus sold today are hybrids which are commonly designated as Gladiolus × hortulanus. At least eight different species have been utilized in breeding modern gladiolus, and the parentage of most cultivars is not known. Plants can be classified by their overall size as well as the size and shape of the blooms. Modern hybrids can be divided into three main groups:
a. Grandiflora hybrids. Funnel-shaped, large-flowered gladiolas with 4-6” wide blooms on 3-6’ tall scapes. Up to 30 flowers per spike. Extensive range of flower colors. Considered the most difficult group to grow in typical garden settings.
b. Nanus hybrids. Miniature hybrids with small flaring blooms reaching up to 3” wide on 1.5’ tall scapes.
c. Primulinus hybrids. Hooded-type flowers held loosely on 2-4’ tall scapes. Butterfly hybrids, often included as a subgroup of the Primulinus hybrids, feature flowers with ruffled petals and contrasting throat blotches and other markings on 2-3’ tall scapes.
Genus name comes from the Latin word for a small sword in allusion to the shape of the leaves. The plants are also sometimes called sword-lilies but people generally use the Latin plural gladioli.
Problems
Susceptible to botrytis, crown rot, rust, wilt and mosaic virus. Watch for aphids, mealy bugs, spider mites and thrips. If thrips were a problem during the growing season, consider treating corms with an insecticide prior to storage.
Uses
Beds, borders. Container plant for decks and patios.