Healthy glads make a happy gardener

April 19, 2007



Let me tell you about a plant with spectacular flowering spikes - the gladiola. These beautiful creations are commonly called "glads," which is what I will call them. Glads are also commonly called "sword lilies" because of their long slender leaves. However, glads are not lilies. Lilies are grown from bulbs, and glads are grown from corms.


Bulbs are teardrop shaped, pointed on top and round on the bottom. Corms are shorter and the bottoms are concave. According to the Master Gardener handbook, both bulbs and corms are really the swollen stems of the plant. But, bulbs have fleshy scales (like onions, lilies, daffodils and tulips) while corms are solid (like glads, crocuses and irises) whose scales have been reduced to dry, scale-like leaves.

With this knowledge of the difference between bulbs and corms, we can now learn how to grow tall, elegant glads from corms.

Why grow glads?

There are numerous reasons for growing glads, but I think the most important one is because of the beauty of the jewel-toned blooms. They come in so many different colors, even a light green. To my knowledge there isn't a true blue yet, but I read this was being researched now. There are variegated blooms and solid-colored blooms. They range from a pure white to a purple or red that is almost black.

As for floral displays, the colors will fit any room decor. Glads lend themselves to elegant settings as well as very informal settings. They are used in celebratory settings as well as in more solemn settings. I find glads to be the most versatile flower I know, and one of the easiest flowers to grow.

The Gladiolus natalensis, or parrot gladiolus, produces blooms in a brilliant color combination of yellowish green and red

Glads must have good drainage. They prefer full sun, but will grow reasonably well in light shade. They grow best if you will take time to prepare the location with a soil pH of 6.7 to 7.0. Most of the soil that will produce veggies will also work for glads. They also need good circulation between plants, so don't plant them next to a building since this would restrict airflow.

Prepare your soil as you normally would, either tilling or using a shovel. Mix in some good organics such as composted manure and humus. Also add some slow-release fertilizer. After mixing this, let it set for a few days, and you are ready to start your planting of glad corms.

Getting Started

Dig a hole about 5 to 6 inches deep. Sprinkle some insecticide granules to prevent soil insects from feasting on your glad corm. Mix this in well. Place your glad corm in this hole and cover it with only about 1 inch of your mixed soil. By covering the corms only an inch you will have 2-3 inch holes left in your planting area, but that is the way it should be.

Continue planting additional corms about 5 inches apart until you have finished.

As your glads start to grow and as they put out the little green sword-looking leaves, start to fill in with more soil, being sure you leave part of the green showing. Continue to do this, until you have filled the hole. I know this is a big pain, but in the long run, it will pay you back with strong stems of glads. It is a one-time planting. When you plant your glads using this method, you have a permanent planting of glads.

In my experiences of growing glads, the only pests I have ever had are those pesky little thrips! They are very easy to control using a recommended insecticide. If you don't control them, you will have misshaped blooms or perhaps no blooms at all.

Cutting Glads

Glads may be cut just when the bloom on the bottom of the stem starts to open. If you wait until the entire stem is in full bloom, it really won't last very long as a cut flower. Leave as much foliage as possible on the plant when you cut the bloom. This will help build up a food source in the corm for next year's bloom.

After Blooming

After your glads stop blooming, and they will only bloom one time each year, let the sword-like leaves stay on the plant until they die back naturally. Remember, this is the food source and by removing the leaves, you remove the food source for the corm. Just maintain good healthy leaf growth throughout the season and you'll be rewarded with more glads next year. These spectacular flowers really are easy to grow.

  Set corms about 5-6 inches deep and cover them with 2-3 inches of soil.

  Backfill the hole with more soil as the stem grows, never completely covering the sword-like leaves.

  Mound up the soil around the stem after the hole is filled. This will take a few weeks.

  By adding another 2-4 inches of soil on top, this will keep the stem straight and strong.


Gladiola corms should be planted from as early as mid-February until the last of April.

1. First planting soil level

2. Second soil level added as growth emerges 2 inches

3. Third soil level added as growth reaches top of bed

4. Mulch mounded around growing sprout

The Gardeners' Dirt is written by members of the Victoria County Master Gardener Association, an educational outreach of Texas Cooperative Extension-Victoria County. Mail your questions in care of the Advocate, P.O. Box 1518, Victoria, Texas 77901; or, or comment on this column at