Clematis, a genus of popular flowering vines, are highly prized by home gardeners for their spectacular blooms and vigorous climbing habit. A common concern for anyone gardening in a region with a deer population is the potential for browsing damage. Understanding whether deer will eat these vines and knowing how to prevent that damage is necessary for maintaining a healthy landscape. This article provides a clear answer regarding the plant’s palatability and offers specific strategies to keep your Clematis thriving and untouched.
Deer Palatability of Clematis
Clematis is generally regarded as a deer-resistant plant, though this does not mean it is deer-proof. Deer typically avoid this vine in favor of other, more palatable plants available in the garden or the wild. Resistance, in this context, refers to a low preference rating.
However, the preference for any plant shifts based on environmental conditions and the availability of other food sources. During periods of drought, harsh winter conditions, or when deer populations are dense, deer become opportunistic feeders. In these stressful times, a hungry deer may consume plants they would normally ignore. Therefore, young, tender Clematis shoots or new growth on established plants can still be vulnerable to browsing.
Chemical Deterrents and Plant Toxicity
The natural avoidance behavior deer exhibit toward Clematis is rooted in the plant’s chemical composition. Clematis belongs to the Ranunculaceae family, which contains compounds that make the plants unappetizing. The plant contains a glycoside called ranunculin.
When the plant tissue is chewed or damaged, ranunculin is converted into protoanemonin. This compound is a volatile substance that gives the plant a bitter taste deer find highly unpleasant. If a deer consumes enough, this irritant can cause mild oral irritation, excessive salivation, and minor gastrointestinal distress. This built-in chemical defense is usually enough to deter deer from taking more than a small, exploratory bite.
Identifying Deer Browsing Damage
Accurately diagnosing the cause of plant damage is the first step toward a solution, as damage from deer can be confused with that from rabbits or voles. Deer lack upper incisor teeth, meaning they cannot make clean, precise cuts when they feed. When a deer browses, it grips the plant material between its lower incisors and a hard upper dental pad, then tears the foliage away.
This feeding method leaves a distinctive signature: torn, ragged, or shredded stem ends and leaves. In contrast, rabbits and voles, which have sharp incisors, leave behind a smooth, clean cut. Deer browsing damage typically occurs at a height of up to six feet, whereas smaller mammals tend to feed closer to the ground. Finding other evidence, such as elliptical deer droppings or heart-shaped hoof prints near the damaged vine, further confirms a deer as the culprit.
Protecting Clematis in High-Traffic Areas
When Clematis is repeatedly browsed, physical barriers offer the most reliable form of protection. For newly planted or young vines, surrounding the base with a temporary wire cage or mesh netting can prevent browsing until the vine is established. Training the Clematis onto a tall structure like a trellis or arbor can also help lift the bulk of the foliage above the typical browsing height.
The use of commercial deer repellents is another effective strategy, especially when applied consistently to new growth. These repellents typically work by taste, odor, or both. Repellents must be reapplied frequently, usually every few weeks and after heavy rain, to maintain their efficacy. It is beneficial to rotate between two or three different repellent formulations over the growing season to prevent deer from becoming accustomed to a single deterrent.
Strategic planting can also help by placing the Clematis near other plants that deer actively avoid, such as those with strong scents or coarse foliage. Companion planting with herbs like lavender or sage can create a less inviting perimeter. Using a fine mesh deer netting draped over the trellis during the off-season or a time of high deer activity provides an immediate physical deterrent against browsing.