Gladiolus

Gladiolus

Also known as: Sword Lilies

A beautiful cut summer flower that's seen in vases around the continent, the corm-grown gladiolus is part of the iris family and has over 260 species in the genus. Gladiolus, or gladioli in the plural, is native to South Africa and sub-Saharan Africa. Gladiolus means "little sword" in Latin, referring to the flower's spike of feathery, lily-like blossoms.

Gladioli come in three categories: grandiflorus, nanus and primulinus. Within the grandiflorus group, gladioli can range in size from miniature to giant. Giant flower spikes are those that are sold commercially, as cut flowers. However, the gladiolus doesn't have to be a flower spike – some varieties of the plant have one or two flowers on the stem and resemble their cousin, amaryllis. Gladioli have also been used over the years for medicinal reasons, notably to relieve colic.

Gladiolus blossoms, while feathery and very showy, can be orange, red, white, pink, peach, purple, blue, and bicolored. Often, they will have picotee markings, with the margin of the petals being a different color than the petal itself. The foliage is dark green and pointed, with the flowers growing in a column on the stem. Gladioli bloom in the spring and summer. Depending on the variety, they can grow to a height of 48 inches and should be spaced 5 inches apart.

Growing Gladioli

The plant requires full sun to partial shade and fertile, well-drained soil. The corms should be planted 3 to 6 inches deep and watered freely. You may have to stake the tallest cultivars. You will need to apply a high-potash liquid fertilizer continuously to help the plants grow. Successive mass plantings of gladioli are recommended to extend the blooming season.

Recommended Varieties

There are over 10,000 different cultivars in all three categories. Some of the most beautiful include "Cote d'Azur", which has light blue flowers; "Gold Finch", which has lemon yellow flowers; "Happy Time", which has bicolored red and cream flowers, and "Lady Lucille", which has bicolored pink and white flowers. All gladioli will brighten up any garden, however consulting a garden design professional would ensure you find the right flower for your garden.

Landscape Design Tips

Gladioli look beautiful at the back of the garden border, where they can tower over smaller, contrasting plants. They also brighten a cutting garden.

Gardening Zones

Gladioli are hardy in zones 8 to 10.

Pests and Problems

The flowers can suffer from gladiolus corm rot, gray mold, viruses, aster yellows, aphids, spider mites and thrips.