Feverfew (Tanacetum parthenium) is a popular perennial plant chosen by gardeners for its attractive, abundant, daisy-like blossoms and bright green foliage. As deer populations increase, gardeners must consider which plants are likely to survive browsing pressure. A common concern is whether this perennial can be included in a landscape without becoming a frequent target of hungry deer.
Feverfew’s Status as a Deer Deterrent
Feverfew is a deer-resistant plant, making it a favorable choice in areas with high browsing activity. The plant’s natural defense mechanism is rooted in its chemistry, which results in a strong, pungent aroma and an intensely bitter taste. These characteristics signal unpalatability to deer, causing them to pass it over for more appetizing forage.
The primary compounds responsible for this deterrent effect are sesquiterpene lactones. The most prominent is parthenolide, which is highly concentrated in the plant’s superficial leaf glands. Parthenolide can constitute up to 85% of the plant’s total sesquiterpene content. This high concentration of bitter compounds enforces a strong natural avoidance behavior.
Conditions Where Deer May Still Browse
While feverfew is generally avoided, “deer resistant” is not a guarantee of being “deer proof.” The primary factor that overrides avoidance is extreme nutritional stress or scarcity. During harsh winters, when snow cover limits access to preferred food sources, deer may browse less palatable plants, including feverfew, simply to survive.
High local deer populations also increase pressure on available vegetation. Deer may sample the plant out of curiosity or desperation, causing damage even if they ultimately reject the taste. A hungry deer will often take exploratory bites before deciding it is not worth consuming, resulting in noticeable, though often incomplete, damage to the foliage.
Common Pests That Do Target Feverfew
While larger herbivores typically avoid the plant, feverfew remains susceptible to several common garden insect pests. Aphids are frequent visitors, sucking the sap from the stems and new growth, which can lead to distorted leaves and stunted development. The presence of aphids often leaves behind a sticky residue known as honeydew.
Spider mites, specifically the two-spotted spider mite (Tetranychus urticae), can also be a problem, especially in hot, dry conditions. These tiny arachnids feed on the leaf tissue, causing stippling, bronzing, and overall decline in plant health. Other insects that may target the foliage include whiteflies and leaf-mining flies, which create visible tunnels or trails within the leaf structure as they feed. Monitoring for these smaller pests is necessary to maintain the plant’s health.