Basil is a highly favored herb in home gardens for its culinary uses and distinct, appealing aroma. Gardeners often consider this plant to be naturally resistant to deer browsing, which is generally accurate. This resistance is not absolute, however, and depends on environmental factors and the specific plant characteristics. Understanding basil’s deterrent properties and knowing when to introduce protective measures is important for a successful harvest.
Basil’s Natural Deterrents
Basil’s inherent resistance to deer is directly related to its potent, sharp aroma and flavor. Deer are primarily driven by their sense of smell when foraging, and they tend to avoid plants with strong, pungent odors. The high concentration of specialized compounds within the basil leaves creates a sensory barrier that makes the plant an unappealing food source.
The mechanism of this deterrence lies in the essential oils produced by the plant, specifically compounds like eugenol and linalool. Eugenol contributes a clove-like scent, while linalool provides a floral, slightly spicy note. These volatile organic compounds are concentrated in the foliage, making the taste bitter and irritating to a deer’s palate.
Factors Affecting Deer Resistance
Describing basil as “deer resistant” does not mean it is completely “deer proof” in all situations. Deer will readily consume plants they usually avoid if their preferred food sources become scarce. This happens during periods of drought, deep snow cover, or in areas with extremely high deer populations, a condition known as high deer pressure.
A basil plant’s maturity also plays a role in its level of resistance. Younger, more tender basil seedlings contain lower concentrations of the bitter essential oils and may be sampled by deer before the full deterrent mechanism develops. While all basil varieties generally share this resistance, highly fragrant types, such as Thai or Cinnamon basil, may offer a slightly stronger deterrent effect than common sweet basil.
Physical and Sensory Protection Methods
When natural resistance is insufficient, gardeners must employ physical or sensory protection methods to safeguard their basil plants. For comprehensive defense, physical barriers are the most reliable solution, especially in locations where deer frequently browse. A fence must be at least eight feet high to reliably prevent white-tailed deer from jumping over it.
For smaller garden beds or containers, a more manageable option involves creating a cage or netting enclosure over the plants. This physical structure makes accessing the foliage difficult and discourages the deer from attempting to feed. Additionally, some gardeners find success with a double-fence system, using two four-foot fences spaced about four feet apart, which confuses the deer’s depth perception and willingness to jump.
Sensory deterrents offer a non-lethal, secondary line of defense that relies on taste and smell. Commercial and homemade repellents often utilize ingredients that deer find offensive, such as putrescent egg solids or capsaicin from hot peppers. The smell of rotten eggs mimics the presence of a decaying animal or predator, triggering an instinctive avoidance response in the deer.
Capsaicin-based sprays create an unpleasant, burning sensation upon tasting the plant, teaching the deer to avoid that food source. It is helpful to rotate between different types of repellents, such as switching from an egg-based scent deterrent to a capsaicin-based taste deterrent. This rotation prevents deer from becoming habituated to a single stimulus, maintaining the effectiveness of the protection method.
Other Aromatic Herbs Deer Avoid
Basil is not the only garden herb that deer tend to leave alone due to its strong aromatic properties. Many other culinary herbs from the Mediterranean region share the same chemical defense mechanism. These strong-smelling, often slightly bitter-tasting plants are typically ignored by foraging deer.
Planting these aromatic herbs alongside basil can intensify the overall sensory barrier, creating a more uninviting environment for deer. Lavender and lemon balm are also generally avoided, offering gardeners a wide selection of resistant plants.
Common Avoided Herbs
Herbs that are excellent choices for planting near vulnerable garden areas include:
- Rosemary
- Thyme
- Sage
- Oregano
- Mint