Gladiolus, with their towering flower spikes, are a popular addition to many gardens, but their underground storage organs (corms) are a frequent target for foraging pests. Gardeners often wonder if the damage they discover is the work of common backyard rodents. This article addresses the specific threat posed by squirrels to gladiolus plantings.
Do Squirrels Really Eat Gladiolus Bulbs?
Squirrels commonly eat or disturb gladiolus corms, making them a significant threat to newly planted beds. These underground storage structures are highly attractive because they are nutrient-dense, providing a rich source of starch and carbohydrates. This makes them an easy and accessible meal, especially during the fall planting season.
The problem is twofold: direct consumption and caching behavior. Squirrels often partially or completely consume the corms, leaving behind evidence of their meal. They also frequently dig up and move the corms to bury them as part of their winter food storage strategy, effectively removing the plant from its intended location. This caching activity is often triggered by the scent of the newly disturbed soil, signaling an easy opportunity for food gathering.
Identifying the Source of Bulb Damage
Confirming a squirrel as the culprit requires examining the damage pattern, which is distinct from other pests. Squirrel activity is characterized by shallow, messy digging, often leaving the soil scattered and disturbed around the planting hole. Partially eaten corms or fragments may be left near the surface where the squirrel finished its meal.
This differs from damage caused by voles, which are small rodents that eat corms completely underground without disturbing the surface significantly. Vole damage is found in a clean, excavated hole directly into the side of the corm, or the entire corm may be gone. If the damage is superficial and includes messy topsoil disturbance, a squirrel is the likely offender.
Strategies for Protecting Plantings
The most effective way to prevent squirrel damage is by implementing physical barriers to block access to the corms. One common method involves laying chicken wire or hardware cloth directly over the planted area, securing the edges with stakes or heavy objects. The mesh size must be small enough, such as half-inch hardware cloth, to prevent the squirrel from digging through it.
Alternatively, you can create underground cages by lining the planting hole with hardware cloth before placing the corms inside. Planting the corms deeper than the recommended depth can also deter squirrels, as they prefer not to dig more than a few inches beneath the soil surface. Incorporating sharp, gritty materials, like crushed oyster shells or coarse gravel, into the planting hole makes the soil less appealing for squirrels to dig through.
Repellents that rely on strong odors or taste can offer another layer of protection. Applying a capsaicin-based spray or sprinkling crushed red pepper flakes directly over the newly planted soil may deter squirrels due to the unpleasant taste. Another strategy is to mask the scent of the corms by covering the freshly disturbed soil with a thick layer of shredded leaves or strongly scented mulch immediately after planting.