The trumpet vine (Campsis radicans) is a fast-growing, woody vine native to North America, prized for its showy, trumpet-shaped flowers that attract hummingbirds. This aggressive climber quickly covers arbors, fences, and trellises, providing vibrant color throughout the summer. The trumpet vine is typically considered deer-resistant, meaning it is not a preferred food source, though it is not completely immune to browsing.
Why Trumpet Vine is Generally Avoided by Deer
The trumpet vine is unappealing to deer due to both physical and chemical characteristics. The foliage and stems have a distinctively rough texture, which is less palatable than the soft leaves of other garden plants.
A more significant deterrent lies in the plant’s chemical composition. The sap contains compounds that can cause contact dermatitis, leading to skin irritation in both humans and animals. When a deer attempts to consume the foliage, these irritating compounds and a bitter taste deter them from taking more than a small sample.
These natural defenses position the trumpet vine as a low-preference plant. Deer instinctively seek out food sources that offer the highest nutritional return with the least discomfort. The combination of the plant’s rough feel and its irritating chemistry means that deer will consistently choose alternative, more palatable forage when available.
When Deer Might Browse Trumpet Vine
Deer resistance is always a relative measure, not an absolute guarantee of safety. Circumstances that stress the deer population or limit their food options, such as prolonged drought or heavy winter snow cover, can force browsing on normally resistant plants.
In these situations of resource scarcity, deer may be forced to consume almost any vegetation to survive, overriding their natural distaste. The most vulnerable parts of the vine are the new, tender shoots that emerge in the spring or after pruning. This young growth may not yet have the full concentration of irritating compounds found in the mature stems and leaves. When browsing does occur, it is usually light and sporadic, focused on these susceptible tips rather than the entire plant.
Practical Steps for Deterring Deer
If deer browsing becomes an issue, especially on newly planted or young vines, physical barriers provide the most reliable protection. Temporary fencing, such as wire mesh or plastic netting, can be placed around vulnerable plants until they establish a mature structure. Exclusion barriers need to be at least six to eight feet high to be fully effective, since deer can easily clear lower obstructions.
Applying taste- or odor-based repellents can also discourage deer from approaching the vine. Commercial products often utilize ingredients like putrescent egg solids, which create a smell offensive to deer. Homemade solutions, such as mixtures incorporating cayenne pepper, garlic, or a soap-and-egg blend, function similarly by imparting an unpleasant taste or odor to the foliage.
Repellents must be reapplied frequently, especially following rainfall, as the protective coating can wash away. Strategic planting is another passive deterrent. Locating the vine near high-traffic areas or close to a dwelling offers protection, as constant human presence makes deer less comfortable lingering to browse.