Chrysanthemums, commonly known as mums, are popular perennial and annual plants valued for their vibrant colors that extend the season into late autumn. Many homeowners wonder if these flowers can safely exist in a landscape shared with deer. While no plant is entirely immune, the general consensus places mums in a category that is far less appealing than many other garden favorites.
The Deer Resistance Classification
Horticultural lists frequently categorize mums as “rarely damaged” or “seldom preferred” by deer. This classification suggests that while a deer may occasionally sample a chrysanthemum, it is not a primary or favored food source. This highlights that resistance is not a guarantee but a measure of palatability compared to other vegetation.
The distinction between “deer-resistant” and “deer-proof” is crucial when planning a garden. Resistant species, like mums, possess characteristics that encourage deer to browse elsewhere, but they are not impenetrable barriers. Environmental factors or a deer’s individual taste preference can easily override this natural aversion, meaning resistance is always relative to the available food supply.
Sensory Characteristics That Deter Deer
Chrysanthemums are typically resistant due to inherent biological defenses that deer find unappealing. Mums produce volatile organic compounds and secondary metabolites, such as pyrethrins and terpenoids, which create a strong, characteristic aroma. This pungent scent acts as an olfactory deterrent, signaling that the plant may be unpleasant to consume.
If a deer ignores the strong smell, the plant’s taste provides a second defense. The foliage contains phytochemicals that impart a bitter flavor. This bitter profile often results in a deer taking a single bite and immediately rejecting the plant, minimizing damage to the garden.
When Deer Ignore Resistance
Despite natural deterrents, deer will browse on chrysanthemums under certain circumstances. The most common factor overriding aversion is food scarcity, particularly in areas with high deer population density. When preferred native forage is depleted, deer become opportunistic feeders, and even unpalatable plants like mums become a viable option for survival.
The palatability of the plant material also influences browsing behavior. Deer are often more attracted to the tender, new growth, which is softer and more easily digestible than mature foliage. This soft tissue may contain lower concentrations of deterrent chemicals, making it a more accessible snack. Additionally, the flowers are rich in sugars and proteins, offering a quick caloric boost as natural food sources dwindle in the fall.
Management and Protection Strategies
If mums are being browsed despite their resistance rating, implementing protective measures is necessary. One reliable method involves installing physical barriers, such as fencing.
Physical Barriers
For a permanent solution, a fence needs to be at least eight feet high, as deer are capable jumpers. For smaller, localized areas, temporary caging or fine netting placed over the plants can prevent direct access.
Repellents
Repellents offer another layer of defense and are categorized by their mechanism of action. Taste-based repellents, such as those using putrescent egg solids, make the plant unappetizing upon contact and must be sprayed directly onto the foliage. Scent-based repellents mimic the odors of predators or are strong, unfamiliar smells that create an avoidance response. For maximum effectiveness, these products should be applied consistently, often after heavy rain, and rotated with different formulas to prevent deer from becoming habituated to a single deterrent.