Columbine plants (genus Aquilegia) are generally considered to be deer-resistant, though it is more accurate to classify them as deer-tolerant. Deer tend to avoid columbines due to their unique biochemical and physical properties. The foliage and seeds contain cyanogenic glycosides, compounds that can release cyanide when damaged or ingested. While not typically lethal in small quantities, these compounds make the plant unpalatable and potentially irritating to the digestive systems of deer and other herbivores. Consequently, columbines are rarely the first choice for a foraging deer, especially in areas where more preferred vegetation is abundant.
Beyond their chemical defenses, columbines possess several physical traits that contribute to their deer resistance. The leaves are not broad, flat, and succulent like those of hostas or daylilies, which are deer favorites. Instead, they form a lobed, almost delicate, bluish-green mound that is less appealing. Furthermore, the unique structure of the columbine flower, with its backward-extending spurs (which hold nectar), may also be a minor deterrent. While no plant is completely deer-proof, especially in times of extreme hunger or drought, columbines possess a strong combination of traits that make them a much less likely target compared to many other common garden perennials.
It is important to note that "deer-resistant" is a relative term and can vary based on the specific columbine variety and, more significantly, the local deer population pressure. Native columbine species, such as Aquilegia canadensis (Eastern Red Columbine), are often noted for their particularly strong resistance. In regions with very high deer populations where natural food sources are scarce, a hungry deer may sample or even consume columbines out of desperation. Young, tender new growth in the spring is also more vulnerable than established plants. Therefore, while columbines are an excellent choice for a deer-prone garden, they should not be relied upon as a sole deterrent.
To maximize protection for columbines and the rest of your garden, employing a layered defense strategy is most effective. Planting columbines among other strongly-scented, deer-resistant plants like lavender, salvia, catmint, or Russian sage can help mask the scent of more vulnerable plants. The use of physical barriers, such as deer fencing, is the single most reliable method for complete protection. For less severe pressure, motion-activated sprinklers or repellent sprays can be effective, though sprays must be reapplied regularly, especially after rain. Ultimately, combining columbines with other unappetizing plants and supplemental protective measures offers the best chance for a thriving, deer-resistant garden.
