Everything You Need To Know About Growing Gladiolus

Gardeners love growing gladiolus because of their stately, gorgeous stalks flowers that come in a whole range of colors. There are pink, purple, yellow, white, and many more colors of gladioli on the market, so you don’t need to settle for one color.

If you want to sprinkle some vibrant color into your garden, pick gladiolus plants. Why not create a rainbow effect with several of them?

Fun Facts About Gladiolus

Gladiolus are native to Africa, Europe, and the Mediterranean. They are perennial plants that grow from corms. The corms have a paper-like texture on the exterior that protects them, kind of like garlic or onions do.

You can find over 300 different species of this flowering plant all over the world, but you’ll only find a few particularly easy-going, colorful species in home gardens. Most of the gladioli that you find in home gardens are hybrids of several species.

Common species include common cornflag (The common gladioli), Italian (G. italicus), and ever-flowering (G. sad).

The flowers bloom from late spring or early summer until frost.

Most can be grown in USDA Hardiness Zones 7-10, but there are some that can grow outside of this range. In other Zones, you can grow them as annuals or dig up and store the corms somewhere warm.

Best Hybrids and Species to Consider

Like we mentioned, there are lots of options for growing gladiolus plants. Here is a list of some fabulous options:

• Yellowstone (Gladiolus x gardener): Sunshine yellow blossoms on five-foot stalks.
• Abyssinian (G. murielae): Petite, fragrant white blossoms, and three-foot stalks.
• Alaska (G. x gardener): Large white, ruffled flowers. The plant grows up to four feet tall.
• ‘Purple Flora’: Five-foot tall stalks covered in deep, dark purple flowers.
• ‘Green Star’: Bright lime green blossoms on five-foot stalks.
• ‘Black Star’: Five-foot tall stalks featuring nearly black, dark burgundy flowers.
• ‘Espresso‘: Bold, dark red flowers emerging from five-foot-tall stalks.
• Peacock Orchid (G. acidanthera): White blossoms with a maroon heart, heavily fragrant. The plant grows up to three feet tall.

Planting Corms

When purchasing, evaluate the size of the corms. Ideally, you want them to be large, plump, and firm. Think of it this way, the larger the corm, the better chance you have of spectacular blooms!

Aim for a corm that is about five inches in diameter.

Now it’s time to plant. First of all, you need to pick the right time for planting. The best season for starting gladioli is spring, but you can start them indoors sooner.

Normally, it takes 60-90 from planting to see the flowers start blooming after you plant the corm.

Plant in the spring as soon as the ground can be worked and the last projected frost date has passed. If you live in Zone 7 or higher, you can also plant them in the fall.

Where to Plant Gladiolus

Gladiolus corms need full sun exposure and medium soil moisture to reach their full potential. Even though these plants can adapt to different soil conditions, their preferred climate is well-draining soil with neutral pH levels.

Even though most people like to plant these flowers in soil, it’s also possible to grow them in containers if you have the right equipment. If this is a growing method that appeals to you, use a large pot filled with a standard potting mixture. A 10-gallon pot is perfect.

Alternatively, you can grow them outdoors as border flowers and in raised beds.

The Planting Process

The planting process starts with digging the correct size hole for your corms. Aim to create a hole that is at least three times as wide and deep as the corm. Then, amend the removed soil with well-rotted compost. Place the corms about five inches deep with the tip facing up and fill the hole up with the amended soil.

As a general rule, five or six inches of space between your corms is the sweet spot for getting a full display of flowers without leaving one looking isolated from the rest. For a stunning visual impact, a cluster of seven corms will give you a pleasing aesthetic.

For pots, plant two or three with different colors to draw the eye with lots of color, or use one color to create a more contemporary, simple effect.

Caring Tips for Gladiolus

As soon as you notice leaves growing on your gladiolus plants, you should think about giving them a little extra support to maintain their structure. The easiest way to provide some support for gladioli is with bamboo canes and string.

You can find these materials easily online or at your local garden store.

Corms need frequent watering when they’re growing. This is especially important during the warmer seasons when most plants need more moisture.

Plants in containers need even more watering because they tend to dry out more quickly. Test the soil moisture levels every day or so to see if the plants need watering.

When it comes to fertilizer, supply your gladiolus plants with a balanced liquid plant food as the blossoms just begin to form. This will give the flowers nutrients to help them form lovely blossoms.

Give your gladioli a mulch covering to provide additional nutrients, keep the soil from drying out, and suppress weeds.

Common Gladiolus Pests and Diseases

While they’re generally pretty tough and growing gladiolus is easy, there are some pests and diseases to watch for. Here are the most common:

Pests

Thrips are a frustrating but common pest that attacks gladiolus. While they aren’t easy to spot, they leave distinctive pale patches on plants that have a silver appearance in the light.

When infested, the buds might fall or the flowers might turn brown. To learn how to eliminate them, head to our guide.

Aphids are another common pest. These small sap-sucking insects spread disease and cause stippling and stunted growth. As with thrips, we have a guide to help you through identifying and getting rid of an infestation.

Scalewhile not as common as aphids, are also known to feed on gladiolus. To learn all about this pesky pest, visit our article.

Diseases

Botrytis blightwhich is caused by the fungus Botrytis gladioluscauses brown spots with red margins, stem rot, and black lesions on the corms underground. Purchase only certified disease-free corms and if you notice symptoms, treat your plant with copper fungicide.

Fusarium yellows starts underground. It’s caused by the fungus Fusarium oxysporum f. sp. gladioliand when this fungus is present, it causes the corm to rot. Aboveground, the flowers might not develop normally and the stalk will be curved.

Leaf spots (Stemphylium botryosum and Curvularia trifolli f. sp. gladiolus) thrives when the weather is warm and wet. It causes yellow spots with brown centers and these spots can spread and kill the leaves. Liquid copper can help you get rid of it.

Harvesting Gladiolus Flowers

Harvesting the cut flowers of your gladiolus plants is part of the fun of growing them. You can start to pick the flowers when the first florets begin to open. Cutting them in the morning will give you a fresh harvest and better quality flowers.

Leave at least four leaves to ensure the continuity of corm development.

Place the flowers in warm water to prevent them from wilting. Move them to a cold, dark place for a few hours before arranging a bouquet. This will also them to harden up before being put on display.

Afterward, you can either keep them in your home in a vase or gift them to a loved one as a surprise!

These magical flowers will brighten up anyone’s day, and all the effort of growing them will be worth it when you have a fresh bouquet on your dining room table. All you have to do is follow this guide to have your own gladiolus flower collection!