Introduction
The midsummer garden reaches its peak when the tall, elegant spikes of gladiolus begin to unfurl. These sun-loving flowers offer a rainbow of colors, from soft pastels to vibrant bicolors, and they make some of the best cut flowers for your home. At Longfield Gardens, we enjoy seeing these classic favorites bring height and drama to garden borders every year. Growing them is a rewarding experience for any gardener, provided you can keep the local wildlife from turning your planting site into a snack bar.
While many animals might eye your garden, voles are one of the most common challenges for those growing gladiolus. Because these flowers grow from starchy underground stems called corms, they are a primary target for hungry rodents. This guide will help you identify vole activity and show you the most effective, simple ways to protect your plants. By understanding how voles behave and using a few physical barriers, you can enjoy a full season of spectacular blooms. For help matching planting time to your climate, see our Hardiness Zone Map.
Introduction
To answer the most pressing question first: yes, voles do eat gladiolus corms. In fact, along with tulips and lilies, gladiolus are among their favorite foods. While we often call them "bulbs," gladiolus actually grow from corms, which are solid, thickened underground stems that store energy for the plant. To a vole, these corms are dense, nutrient-rich packages of food that are easy to find just below the soil surface.
Voles are small, mouse-like rodents with short tails and stout bodies. Unlike moles, which primarily eat grubs and worms, voles are strict herbivores. They spend their days searching for roots, seeds, and juicy corms. Because they remain active all year long and do not hibernate, they can be a persistent presence in the garden from spring planting through the winter months. If you are planning an order, you can review Shipping Information before you plant.
If you have noticed your gladiolus spikes failing to emerge or discovered that a plant suddenly topples over because its base has been chewed away, you likely have a vole in the area. Protecting your garden doesn't have to be a source of stress. Most vole issues can be solved by making the corms harder to reach and the garden less inviting as a habitat.
Identifying Vole Damage and Activity
Before you can protect your gladiolus, you need to be sure that voles are the actual culprit. It is easy to confuse vole activity with that of moles or squirrels, but each animal leaves different clues. Identifying the "who" helps you choose the right "how" for your protection strategy.
Visual Clues Above Ground
Voles are famous for creating "runways." These are narrow, flattened paths in the grass or mulch that look like tiny highways. These paths allow the voles to move quickly between their burrow entrances and their food sources while staying hidden from predators like hawks or cats. If you see these little tracks leading toward your flower beds, voles are likely visiting your garden.
Underground Tunnels
Voles are excellent diggers, but they prefer to stay close to the surface. You might notice the soil feels "spongy" or soft when you step on it. They also frequently use abandoned mole tunnels. While the mole did the heavy lifting of digging the tunnel to find worms, the vole uses that same tunnel as a convenient subway system to reach your gladiolus corms.
Disappearing Plants
The most frustrating sign of vole activity is the total disappearance of a plant. You might plant a dozen gladiolus corms in the spring, only to have eight of them emerge. When you dig down to see what happened to the others, you may find only a hollow space or a few chewed fragments of the husk. If the plant does grow and then suddenly wilts or falls over, check the base. Voles often chew the tender stem right where it meets the corm.
Why Voles Target Gladiolus
Understanding why these specific plants are targets helps you better defend them. Gladiolus corms are essentially storage tanks for the plant’s energy. They are high in carbohydrates and moisture, making them an ideal food source for a small mammal that needs to fuel its high metabolism.
Voles are also prolific breeders. A single female can have several litters in a year, and the population can grow very quickly if there is a steady food supply. A garden bed full of freshly planted gladiolus corms is exactly the kind of "all-you-can-eat" environment that encourages voles to move in and stay.
Furthermore, gladiolus are typically planted at a depth of about 4 to 6 inches. This is the "sweet spot" for voles, as it is deep enough for them to stay hidden while digging but shallow enough that they don't have to work hard to find their meal. Because the soil in a garden bed is usually loose and amended with compost, it is much easier for voles to tunnel through than the hard-packed soil found under a lawn.
The Best Physical Barriers for Protection
The most reliable way to stop voles is to use a physical barrier that they cannot chew through or dig under. While repellents can work for a short time, a sturdy barrier provides permanent peace of mind.
Hardware Cloth Cages
One of the most effective methods is to plant your gladiolus corms inside "cages" made of hardware cloth. This is a sturdy wire mesh found at most hardware stores. For voles, you should use a mesh size of 1/4 inch or 1/2 inch. Anything larger may allow the small rodents to squeeze through.
To make a cage, cut a piece of hardware cloth and fold it into a box shape without a lid. Dig your planting hole slightly larger and deeper than usual. Place the wire box into the hole, add an inch of soil at the bottom, and then set your gladiolus corm inside. Fill the rest of the cage and the hole with soil. The wire prevents the vole from reaching the corm from the sides or the bottom, while the plant’s stem can grow freely up through the top.
Lining Large Planting Beds
If you are planting a large drift of gladiolus, making individual cages might feel like too much work. In this case, you can line the entire planting area. Excavate the bed to a depth of about 8 inches. Lay the hardware cloth across the bottom and bring the edges up the sides of the hole, so they sit just below the soil surface. This creates a "basket" for your entire flower bed that keeps burrowing rodents out.
Using Nursery Pots
For a quick and easy version of a cage, use plastic nursery pots. Cut the bottom out of a 6-inch or 1-gallon plastic pot. Sink the pot into the ground so the rim is just level with the soil surface. Plant your corm inside the pot. While a very determined vole could eventually chew through plastic, they usually find it easier to move on to a different area rather than working through the side of a pot.
Key Takeaway: Physical barriers are the only 100% reliable way to stop voles. Using 1/4-inch hardware cloth to create planting cages prevents rodents from reaching corms while allowing roots and stems to grow naturally.
Using Gritty Materials as a Deterrent
Voles have sensitive paws and noses. They prefer to tunnel through soft, moist soil that is easy to move. You can use this to your advantage by changing the texture of the soil immediately surrounding your gladiolus.
Sharp Gravel and Grit
When you dig your planting hole, try mixing in a handful of sharp, gritty material. Crushed oyster shells, coarse chicken grit, or specialized products made of expanded slate are all excellent choices. These materials are uncomfortable for voles to dig through.
Surrounding the corm with a one-inch layer of this grit creates a "scratchy" barrier. Most voles will stop digging as soon as they hit the sharp edges, leaving your gladiolus safe. As an added bonus, this grit improves drainage around the corm, which helps prevent rot during rainy spring weather.
Large-Scale Soil Amendments
If your garden has a high vole population, you can incorporate coarse sand or fine gravel into the entire planting bed. By making the overall soil texture less "fluffy," you make it much less attractive for voles to build their tunnel systems there.
Cleanliness and Habitat Management
One of the simplest ways to manage voles is to change the environment around your garden. Like most small animals, voles are prey for many predators. They are cautious and will only stay in areas where they feel safe and hidden.
Tidy Up the Garden
Voles love "messy" gardens. Long grass, piles of fallen leaves, and thick layers of mulch provide the perfect cover for them to move around without being seen by hawks, owls, or cats. By keeping your lawn mown and clearing away dead plant debris, you remove their hiding spots.
Manage Your Mulch
While mulch is great for moisture retention, a very thick layer (more than 3 inches) is an open invitation for voles. In the winter, voles will often nest inside deep mulch. To protect your gladiolus, keep mulch levels thin, especially near the stems of your plants. For more guidance, see How to Choose the Best Mulch for Flower Gardens. If you are in a cold climate and use mulch to protect corms over winter, wait until the ground has actually frozen before applying it. This prevents voles from setting up their winter home in the cozy, unfrozen soil under the mulch.
Strategic Bird Feeder Placement
Bird feeders are wonderful for bringing life to the yard, but they also drop a lot of seeds and hulls on the ground. This "free food" attracts voles and other rodents to the area. Once they finish the seeds on the surface, they will naturally start looking for roots and bulbs nearby. Try to place your bird feeders in an area of the yard away from your most prized flower beds.
Companion Planting: Using Nature’s Defenses
In the world of gardening, "right plant, right place" also applies to what you plant next to your gladiolus. Some plants are naturally unappealing to voles because of their taste, smell, or toxicity. Using these as a "living shield" is a smart way to protect your flowers.
The Power of Narcissus (Daffodils)
Daffodils are the gold standard for rodent-resistant gardening. They contain a bitter, toxic alkaloid called lycorine. Almost no animal, including voles, will eat a daffodil bulb. By planting a perimeter of daffodils around your gladiolus, you create a zone that voles will generally avoid. Even though the daffodils bloom earlier in the spring, their bulbs remain in the ground all summer, acting as a permanent deterrent.
Alliums and Fritillaria
Members of the onion family (Alliums) have a strong scent that voles find unpleasant. Planting ornamental alliums or even culinary chives and garlic near your gladiolus can help mask the scent of the tasty corms. Similarly, Fritillaria imperialis (Crown Imperial) has a very strong, musky odor that is famous for repelling rodents. Placing a few of these around your garden can act as a "no-trespassing" sign for voles.
Natural Repellents and Deterrents
If you prefer not to build cages or move soil, there are several topical repellents you can try. While these require more maintenance than physical barriers, they can be a helpful part of a larger strategy.
Castor Oil
Castor oil is a common ingredient in many commercial vole repellents. It doesn't harm the animals, but it makes the soil and the plants smell and taste unpleasant to them. You can buy castor oil in liquid or granular form. For the best results, apply it to the soil surface and then water it in deeply so it reaches the root zone. Remember that these treatments need to be reapplied after heavy rain or according to the package directions.
Capsaicin and Garlic
Voles have a keen sense of smell and taste, and they generally dislike anything spicy or pungent. Some gardeners have success adding red pepper flakes or garlic powder directly into the planting hole when they set out their gladiolus corms. You can also find sprays made with hot pepper extract to apply to the base of emerging plants.
Predator Scents
Since voles are a primary food source for many animals, they are very sensitive to the scent of predators. Commercial products containing the urine of foxes or coyotes can sometimes scare voles away from a specific area. However, these scents dissipate quickly and may not be enough to stop a very hungry vole if your gladiolus are the only food source available.
Container Gardening: The Ultimate Vole Bypass
If your garden is a "hot zone" for vole activity and you find physical barriers too difficult to install, consider growing your gladiolus in containers. This is one of the most effective ways to guarantee your corms remain safe.
Advantages of Pots
By elevating your plants in pots, you take the corms completely out of the vole's underground environment. At Longfield Gardens, we often recommend containers for gardeners who want to enjoy flowers on their patio or deck while avoiding soil-based pests. Gladiolus look stunning in large pots, especially when grouped together for a concentrated burst of color.
Pot Selection and Placement
Choose a pot that is at least 10 to 12 inches deep to provide plenty of room for the roots and to help anchor the tall flower spikes. Because gladiolus can become top-heavy when in full bloom, a heavy ceramic or stone pot is a better choice than a lightweight plastic one. Place the pots on a hard surface like a patio, or use "pot feet" to lift them slightly off the soil. This prevents voles from crawling up through the drainage holes at the bottom.
What to do next:
- Assess your garden for vole runways or spongy soil.
- Purchase 1/4-inch hardware cloth if you plan to plant in the ground.
- Clear away thick mulch or debris from your planting areas.
- Select a heavy, deep container if you prefer to avoid the ground altogether.
Aftercare and the Importance of Winter Storage
Protecting your gladiolus doesn't end when the flowers fade. Because gladiolus are tender perennials (hardy only in USDA zones 8–10), most gardeners in the US need to lift the corms in the fall and store them indoors for the winter. This is actually a great way to protect them from voles.
Lifting the Corms
Once the foliage has turned yellow or been hit by a light frost, carefully dig up the corms. You will notice that the original corm you planted has withered away, and a new, larger corm has formed on top of it. This new corm is what you will save for next year.
Cleaning and Curing
Shake off the excess soil and cut the stems back to about an inch above the corm. Let the corms "cure" or dry in a warm, airy spot out of direct sun for about two weeks. During this time, the outer skin will toughen up. This drying process is essential for preventing rot and mold during storage.
Safe Winter Storage
Once cured, store the corms in a cool, dry place that is protected from freezing temperatures. A basement or unheated garage is usually ideal. To keep them safe from indoor mice or voles, store them in mesh bags or open boxes filled with peat moss or sawdust. Do not store them in airtight plastic bags, as they need air circulation to stay healthy.
Realistic Expectations for Wildlife Management
Gardening is a partnership with nature, and nature can sometimes be unpredictable. While the methods described above are highly effective, it is important to remember that no strategy is 100% "rodent-proof" in every situation. If an animal is hungry enough, it may try to bypass barriers or ignore unpleasant smells.
Success in the garden often comes from a "multi-layered" approach. Instead of relying only on one repellent, try combining it with a physical barrier and some companion planting. This creates multiple obstacles for the voles, making your garden the most difficult place in the neighborhood to find a meal. Most voles are looking for an easy win; if you make them work for it, they will likely move on to easier targets elsewhere.
We believe that gardening should be a source of joy, not a battle. By taking a few simple preventive steps at planting time, you can stop worrying about what's happening underground and start looking forward to the beautiful display of color above ground.
Summary of Protection Steps
Protecting your gladiolus from voles is a straightforward process that starts the moment you pick up a trowel. By focusing on physical exclusion and habitat management, you can keep your garden thriving.
- Use Wire Mesh: Plant corms in cages made of 1/4-inch hardware cloth to block access.
- Add Grit: Surround corms with crushed stone or oyster shells to deter digging.
- Keep it Tidy: Remove tall grass and heavy mulch where voles hide.
- Companion Plant: Use daffodils and alliums as a natural deterrent.
- Consider Pots: Use containers on hard surfaces to bypass the soil entirely.
- Store Safely: Lift and store corms indoors in winter to keep them away from rodents.
"A beautiful garden is achievable for everyone. By understanding the simple needs of your plants—and the habits of your local wildlife—you can create a landscape that flourishes season after season."
Whether you are a beginner or a seasoned gardener, we are here to support you in creating your most beautiful yard yet. For more advice on growing healthy, vibrant flowers, visit our gardening guides at Longfield Gardens.
FAQ
How can I tell the difference between a vole and a mole?
The easiest way to tell them apart is by their diet and their tunnels. Moles are carnivores that eat insects and create deep tunnels with visible "molehills" of mounded soil. Voles are herbivores that eat plants and create shallow "runways" that look like little paths on the surface of the grass or mulch.
Will voles eat my gladiolus in the winter?
Yes, voles do not hibernate and remain active all winter. If you live in a warm climate where gladiolus corms stay in the ground, they are a primary food source for voles during the cold months. In colder climates, lifting and storing your corms indoors is the best way to keep them safe until spring.
Are there any gladiolus varieties that voles won't eat?
Unfortunately, all gladiolus varieties are generally tasty to voles. Unlike daffodils, which contain a toxic substance that protects them, gladiolus corms are non-toxic and high in nutrients. This is why using physical barriers like wire cages is so important for this specific plant.
Does "humane" trapping work for voles?
Trapping can help reduce a local population, but it is rarely a permanent solution because new voles will often move into the vacated territory. It is much more effective to focus on "excluding" them from your flower beds with hardware cloth and making the habitat less attractive by removing hiding spots.
