Gladiolus plants are known by several other names, including Gladiola, “Glads”, and even “Sword Lilly”. Why Sword Lily, you might ask? It’s because of their long, sword-like leaves. But, Glads are not members of the lily family. Whatever you like to call them, their showy spikes make them one of the more popular flowers grown in the home flower garden. Gladiolus flowers are native to the mountains of South America. They are widely grown in the U.S. and Europe. Growing Gladiolus from corms is easy. They make for a beautiful, stately flower in the garden and floral arrangements, hence their popularity.
With just a little attention, your glads will burst into a bloom of tall spikes in July or August. Blossoms come in a wide range of colors and bi-colors, including blue. The blossoms will open from the bottom first. Harvest spikes of Gladiolus just before the top blossoms open. The top blossoms will open indoors.
Did you know? You might think that Gladiolus grows from bulbs….wrong! They actually grow from a closely related cousin, the “corm”. See more on Bulbs, Corms, and Rhizomes.
Flowers Bloom: Mid to Late Summer
Flower Colors: There’s a wide variety of colors and bi-colors.
Plant height: 2 to 5 feet tall.
Plant Hardiness Zones: 8 – 11
You’re probably well familiar with bulbs, which reproduce baby bulbs below the mother bulb. Corms, on the other hand, produce new corms on the top of the mother corm. In the fall, dig up Gladiolus corms. Next, separate the new baby corms. Then, allow them to dry. Finally, store the Gladiolus corms in a cool, dry, and dark place until planting time arrives next spring.
Tip: If you are planning a color-coordinated design for your flower garden, sort corms by color, before putting them away.
Bulb Planting Depth: Plant the corms 6 to 8 inches deep with the root side down.
Final Plant Spacing: 6 to 8 inches apart. They tolerate a little crowding. However, plants and flowers are smaller when overcrowded.
Select a planting site that receives full sun. However, Gladiolus will still grow well in partial shade. My glads receive full morning sun before being shaded by the house in the afternoon.
Gladiolus plants grow best in rich, well-draining soil. A little fertilizer helps to stimulate growth, especially if the soil is poor.
Plant Gladiolus in the spring. They can be grown in rows or bunches. They will tolerate a little crowding but will grow bigger if spaced out.
Once planted, your gladiolus should grow well with little attention. Add mulch to help retain water, and to keep the weeds down.
Gladiolus will grow two to five feet tall. But, they are not sturdy plants. The heavily flowered spikes are susceptible to bending and breaking. Protect from the wind, if possible. Tie the spikes to plant stakes, to avoid wind damage. Also, mound soil around the plants after they have grown at least six inches tall. This provides the plant with additional support.
After the plants have died back in the Fall, cut the plants back to the ground. In colder regions, cover the area with a thick layer of mulch to protect the corms from freezing.
Ideal Soil pH: 6.0 – 7.0.
Insect and plant disease are uncommon.