The barberry bush (Berberis genus) is a popular ornamental shrub known for its vibrant foliage and hardiness. When landscaping in areas with a deer population, palatability is important; barberry is generally highly resistant to deer browsing. These shrubs, particularly the widely planted Japanese barberry (Berberis thunbergii), are consistently rated as rarely damaged by deer. This natural resistance makes barberry a favored option for gardeners seeking to minimize browsing damage.
Deer’s Relationship with Barberry
Deer intentionally avoid barberry in most environments, making it a reliable choice for landscapes where other plants are regularly consumed. Horticultural experts agree that barberry is one of the most deer-resistant shrubs available. This means deer will pass over the plant to feed on nearly any other available vegetation.
The avoidance behavior is well-documented, with various types of barberry, including the common Japanese, proving unappealing to white-tailed deer. In a normal foraging scenario, deer select plants that are more palatable and easier to digest. Barberry is often recommended for use near the edges of a property, where deer pressure tends to be highest.
This strong preference for other forage is why barberry is sometimes referred to as “deer-proof,” although no plant is truly immune to browsing. The resistance applies broadly across the species. Homeowners can select various cultivars, such as those with deep burgundy or bright yellow foliage, without compromising the plant’s natural defense against deer.
Natural Defenses of the Barberry Bush
Deer avoid the barberry bush due to a combination of physical and chemical deterrents that make the plant an unpleasant meal. These mechanisms evolved to discourage herbivory. The most immediate physical defense is the presence of sharp, stiff spines located along the stems.
These spines are typically found at the base of each leaf cluster, making it difficult and painful for a deer to grasp the stems or leaves. The thorns are sharp enough to inflict minor injury, which serves as a highly effective deterrent to browsing animals. This physical barrier causes deer to expend too much effort and risk for too little reward.
Beyond the physical structure, barberry contains a potent chemical defense in the form of alkaloids, the most notable being berberine. This compound is concentrated throughout the plant, particularly in the roots and stems, and is responsible for the intensely bitter taste. Berberine acts as a feeding deterrent because it signals to the animal that the plant is unpalatable or potentially toxic, leading to immediate rejection. The presence of this bitter alkaloid is a major factor in the plant’s high resistance rating.
Situational Browsing and Exceptions
While barberry is highly resistant, deer may browse the plant under specific, stressful circumstances. The most common exception occurs during periods of extreme environmental stress, such as severe winter weather with deep snow cover. When preferred food sources are buried or exhausted, a starving deer may reluctantly turn to barberry as a last-resort food source.
Browsing can also occur on the newest growth of the plant. Young shoots and tender spring foliage may initially have softer, less developed spines and lower concentrations of bitter alkaloids compared to mature stems. Deer may sample this new material, resulting in minor damage that is usually not severe enough to harm the plant significantly.
Young or stressed barberry plants may also be more susceptible to browsing than established, healthy ones. A plant newly installed or one suffering from drought or disease may not have fully developed its defensive structures or chemical potency. In these cases, the deer’s natural reluctance may be temporarily overridden by extreme hunger or the vulnerability of the specific plant.