How To Transplant Gladiolus

If you want to keep your gladiolus blooming beautifully year after year, you need to know how to transplant gladiolus. This simple step-by-step guide will walk you through the entire process, from knowing when to dig them up to replanting them for another spectacular show. Whether you’re moving them to a new bed or storing them for winter, it’s an easy task that makes a huge difference.

Gladiolus, often called “glads,” are stunning summer-blooming bulbs known for their tall flower spikes. But in many climates, they aren’t winter-hardy. Transplanting them—either to store over winter or to thin out a crowded clump—is essential for their health. With just a little know-how, you can ensure your glads return stronger and more vibrant.

This main section covers the complete transplant process. Think of it in three phases: digging up the corms, preparing them for storage or immediate replanting, and finally putting them back in the ground. Let’s break it down.

When is the Best Time to Transplant Gladiolus?

Timing is everything for a successful transplant. Get it wrong, and you could lose your corms.

For Winter Storage: Dig up your gladiolus corms in the fall, after the foliage has turned yellow or brown from a light frost. This is usually about 4-6 weeks after blooming ends. The plant needs this time to send energy down to the corm for next year.
For Dividing in Spring: If you stored corms over winter, transplant them back outdoors in the spring once the soil has warmed up and all danger of frost has passed. Soil temperature should be at least 55°F (13°C).
For Immediate Replanting: You can dig and divide crowded clumps in either fall or spring, replanting the best corms right away if your winters are mild. Otherwise, fall digging for spring planting is safest.

Tools and Materials You’ll Need

Gathering your supplies beforehand makes the job smooth. You likely have most of this already.

A garden fork or spade
Gardening gloves
Pruning shears or sharp scissors
A soft brush (an old paintbrush works)
Newspaper or mesh bags for storage
A cool, dry, well-ventilated storage area (like a basement or garage)
Labels and a marker (trust me, you’ll forget which is which!)

Step-by-Step: Digging Up the Corms

Be gentle during this step to avoid damaging the corms, which are the bulb-like storage organs.

Cut Back Foliage: Start by trimming the gladiolus stems down to about 2-3 inches above the ground using your shears. This makes handling easier.
Loosen the Soil: Insert your garden fork into the soil about 6-8 inches away from the base of the plant. Gently lever the fork back to loosen the soil and lift the clump. Avoid driving the fork directly through the corms.
Lift the Clump: Carefully pull the entire clump of soil and corms out of the ground. Shake off the excess soil gently over your garden bed.

Step-by-Step: Cleaning and Curing

Proper cleaning prevents rot and disease during storage.

Separate by Hand: Gently pull apart the main corm from the smaller cormels (baby corms) attached to it. Also, detach the old, withered corm from the bottom of the new one—it should come off easily.
Brush Off Soil: Use your soft brush to remove most of the dry soil. Do not wash them with water, as added moisture can cause molding.
Let Them Cure: Place the corms in a single layer on newspaper or a screen in a warm, dry, airy spot out of direct sun. Let them cure for about 2-3 weeks. This allows the outer husk to dry and toughen up.

Step-by-Step: Sorting and Storing

Not every corm is worth keeping. Be selective for the best blooms.

Discard any corms that show signs of rot, disease, or severe damage.
Keep the plump, firm corms that are at least an inch or more in diameter. These are most likly to flower next year.
You can save the smaller cormels if you wish, but know they may take 2-3 seasons to reach blooming size.
Dust the corms lightly with a fungicide powder (like garden sulfur) to prevent fungal issues. This step is optional but recommended.
Store them in paper bags, mesh onion bags, or old nylon stockings. Label each bag with the gladiolus variety and color. Good air circulation is crucial.
Keep the bags in a dark, dry place with temperatures between 35-45°F (2-7°C). A cool basement or unheated garage is perfect.

Step-by-Step: Replanting Your Gladiolus

When spring arrives, it’s time to plant again. Here’s how to do it right.

Inspect Stored Corms: A month before your last spring frost date, check your stored corms. Toss any that have shriveled or gotten moldy.
Choose a Sunny Site: Select a planting location that gets full sun (at least 6-8 hours daily) and has well-draining soil. Glads hate soggy feet.
Prepare the Soil: Work the soil to a depth of about 12 inches. Mix in some compost or aged manure to improve fertility and drainage. A balanced, slow-release fertilizer can be worked in at this time too.
Plant at the Right Depth: Plant corms 4-6 inches deep, with the pointed end facing up. Space them about 6-8 inches apart. For a continual bloom, you can plant a few corms every two weeks until early summer.
Water and Mulch: Water the newly planted corms thoroughly. Apply a light layer of mulch to conserve moisture and suppress weeds. Water regularly throughout the growing season, especialy during dry spells.
Provide Support: As the flower spikes grow, they may need staking. Install stakes early to avoid damaging the roots later.

Tips for Transplanting Gladiolus Successfully

A few extra pointers can make all the difference between good results and great ones.

Always rotate your gladiolus planting site every few years to prevent soil-borne diseases.
When digging, if you accidentally slice through a corm, you can dust the cut with fungicide and still store it. It might still grow.
If you have voles or moles, planting gladiolus corms in submerged wire cages can protect them from being eaten.
Don’t be tempted to braid or tie the foliage before it dies back naturally. This interfers with the plant’s energy storage process.

Troubleshooting Common Transplant Issues

Sometimes things don’t go perfectly. Here’s what might go wrong.

Corms Rotting in Storage

This is usually caused by excess moisture or poor air circulation. Ensure corms are fully cured and dry before storage. Check them monthly and remove any soft ones immediately to prevent spread. Store in mesh bags, not plastic.

Gladiolus Not Flowering After Transplant

This can be frustrating. Common causes include planting corms that are too small (use larger, plump ones), not enough sun (they need full sun), or soil that is too poor or too nitrogen-rich, which promotes leaves over flowers. A lack of water during the growing season can also be a culprit.

Foliage Dying Back Too Early

If foliage yellows and dies before fall, it could indicate a disease like fusarium rot or botrytis blight. Remove and destroy affected plants immediately. Do not compost them. Practice crop rotation and ensure excelent drainage to prevent this.

FAQ: Your Gladiolus Transplant Questions Answered

Can you transplant gladiolus while they are blooming?

It is not recommended. Transplanting during bloom shocks the plant and interrupts its energy flow. The bloom will likely wilt, and the corm won’t store energy properly for next year. Always wait until the foliage begins to die back naturally.

How deep should you transplant gladiolus bulbs?

Plant gladiolus corms 4 to 6 inches deep. A good rule is to plant them four times the height of the corm deep. In lighter, sandy soil, plant on the deeper end of that range. In heavier clay soil, you can plant a bit more shallowly, around 4 inches.

Do gladiolus bulbs multiply?

Yes, they do! Each year, the original corm you planted is replaced by a new, large corm. It also produces several smaller corms called “cormels” around its base. These cormels can be saved and grown, but they will take a few seasons to reach blooming size.

What is the best month to plant gladiolus?

The best month depends on your climate. In most areas, plant in spring after the last frost date, when soil is warm—typically from late April through June. You can succession plant every two weeks until early July for a longer bloom period.

Can I leave gladiolus in the ground over winter?

You can only leave them in the ground if you live in a hardiness zone where the soil does not freeze (typically zones 8-10). In colder zones (7 and below), the freezing temperatures will kill the corms. It’s safer to dig and store them.

Transplanting gladiolus is a straightforward garden task that rewards you with healthier plants and more abundant blooms. By following these simple steps—digging at the right time, curing and storing properly, and replanting with care—you’ll enjoy the majestic spikes of color in your garden for many seasons to come. Remember, a little effort in the fall or spring ensures a spectacular show all summer long.