Agastache, commonly known as Hyssop or Hummingbird Mint, is a popular garden perennial prized for its tall, colorful flower spikes and aromatic foliage. While it is a favorite among pollinators like bees and hummingbirds, gardeners often wonder if it appeals to browsing deer. Agastache is highly deer-resistant, making it a reliable choice for landscapes where deer are common.
Is Agastache Truly Deer-Resistant
The strong resistance of Agastache to deer browsing is rooted in its chemistry as a member of the mint family. The leaves and stems contain potent essential oils, which can release intense scents like anise or licorice when crushed. These oils translate to a bitter or unpalatable taste that deer actively avoid.
Deer possess a highly developed sense of taste and smell, allowing them to distinguish between nutritious and potentially harmful plants. The strong compounds in Agastache register as undesirable forage, causing the animal to pass it over in favor of milder-tasting options. Rutgers University classifies Agastache as “Rarely Damaged,” reinforcing its reputation as a plant that consistently withstands browsing pressure.
No plant is entirely deer-proof, regardless of its chemical defenses. Under extreme conditions, such as severe drought or heavy snow cover that depletes all preferred food sources, a starving deer may sample or consume even the most repellent foliage. However, Agastache is typically one of the last plants to be targeted.
Why Deer Avoid Aromatic Plants
Deer have a superior sense of smell, which they use to locate food and detect predators. This highly sensitive olfactory system is easily overwhelmed by the concentrated volatile oils found in aromatic plants like Agastache, lavender, and sage. These strong, pungent scents create an unpleasant environment that signals to the deer that the plant is not worth the effort.
The bitter taste caused by these oils serves as a natural warning sign of potential toxicity or digestive upset. Deer prefer high-nutrition, low-effort forage and generally follow a feeding hierarchy that favors sweet, tender, and easily digestible vegetation. Aromatic herbs and perennials are typically bypassed because they require more metabolic effort to process and offer less immediate reward.
A deer’s feeding habits are influenced by localized factors, including regional population density and the availability of their favorite foods. In areas with low deer pressure and abundant food, they will stick strictly to their preferred plants. Conversely, in regions where deer are numerous and food is scarce, they may become less selective and occasionally nibble on plants they would usually shun.
Garden Strategies for High Deer Traffic Areas
For gardeners in high-traffic deer areas, strategic planting can leverage the natural resistance of Agastache to protect vulnerable specimens. Placing groups of strongly scented plants, such as Agastache or lavender, around the perimeter creates a natural, aromatic barrier. This unpleasant smell may deter deer from investigating the interior where less resistant plants reside.
Physical barriers remain the most effective, though often the most intrusive, method of protection. A fence must be at least eight feet tall to reliably prevent deer from jumping over it. A less noticeable alternative is installing two shorter fences, placed about four feet apart, which confuses the deer’s depth perception and makes them wary of jumping into a confined space.
Actionable deterrents can also discourage browsing. Motion-activated water sprinklers that startle the deer provide a non-chemical solution that trains them to avoid the area. Commercial repellents use foul-tasting or foul-smelling ingredients, often featuring rotten eggs. These should be applied regularly, especially after rain, to maintain an effective protective layer.