Creeping Charlie, scientifically known as Glechoma hederacea, is an aggressive, low-growing perennial that often invades lawns and gardens across North America. Also commonly called Ground Ivy, this plant is recognized by homeowners as a particularly difficult weed to manage due to its rapid, mat-forming growth. As human development expands into suburban and rural areas, interactions between garden plants and local wildlife, particularly white-tailed deer, have become commonplace. This overlap raises a specific question: does this common nuisance weed serve as a food source for deer, or is it merely another plant they bypass while foraging?
Deer Consumption Habits of Creeping Charlie
Deer are highly selective browsers, and Creeping Charlie is generally considered a low-preference food source for these animals. Wildlife experts typically categorize the plant as deer-resistant, meaning deer will rarely choose to consume it when other options are available. The typical diet of a deer is composed of tender, smooth, and nutrient-rich forage, such as hostas, certain shrubs, and young tree shoots.
Observed feeding behavior indicates that Creeping Charlie is one of the last plants a deer will resort to eating. In areas with abundant, palatable vegetation, a deer will almost always bypass this weed. Instances of consumption are usually confined to periods of extreme environmental stress, such as severe winter weather or prolonged drought conditions when preferred food sources are scarce or inaccessible.
During such harsh conditions, deer may sample or lightly browse the plant out of desperation. However, relying on deer to manage an infestation of Ground Ivy is ineffective. The plant’s robust growth quickly outpaces any minimal browsing damage, signaling its lack of value in the deer’s foraging strategy.
Factors Affecting Palatability for Deer
The primary reason deer avoid Ground Ivy relates to its strong chemical and physical properties that act as natural deterrents. As a member of the mint family (Lamiaceae), Glechoma hederacea contains volatile oils, which give the plant a potent, minty, or pungent aroma when the leaves are crushed. Deer possess a highly developed sense of smell and actively avoid plants with such strong, aromatic foliage.
The plant’s taste is also a significant barrier to consumption. These volatile oils contribute a distinct bitterness to the leaves, a flavor profile that deer find highly unpalatable. This bitter taste serves as a biological defense mechanism against herbivory, discouraging animals from taking more than a single, exploratory bite.
Deer tend to prefer plants with smooth textures, but Ground Ivy exhibits a slightly hairy or fuzzy surface on its leaves and stems. This texture contributes to the overall poor sensory experience for the browser. The combination of strong odor, bitter taste, and textural disincentives secures Creeping Charlie’s position on the deer-resistant plant list.
Identifying Creeping Charlie
Accurate identification of Creeping Charlie is helpful for homeowners looking to understand and control this specific weed. The plant is a low-growing, perennial herb that spreads aggressively across the ground using creeping stems, called stolons, which root at the nodes. This rooting behavior allows it to form dense, expansive mats that can choke out turfgrass.
A defining characteristic of Ground Ivy is its unique stem structure. Like all members of the mint family, its stems are square in cross-section. The leaves are situated opposite each other on the stem and are distinctly kidney-shaped or rounded, featuring scalloped edges. When crushed, these leaves release the strong, mint-like odor.
In the spring, the plant produces small, trumpet-shaped flowers that are typically bluish-purple. These flowers are found in clusters where the leaves meet the stem. The plant rarely grows more than a few inches tall, making its low profile and aggressive stolon system the most noticeable features in a lawn or garden setting.
Non-Deer Control Measures for Ground Ivy
Since deer are not an effective form of biological control, homeowners must rely on manual and cultural methods to manage infestations.
Mechanical Removal
Mechanical removal is the most direct approach, involving hand-pulling the plant. This is easiest to do when the soil is moist after a rain. It is important to trace the stolons and remove the entire root system, as even small fragments left behind can regrow.
Cultural Control
Cultural control methods focus on creating an environment where Ground Ivy struggles to thrive. This weed prefers damp, shaded areas, so improving turf density through overseeding and proper fertilization helps grass outcompete the weed. Pruning nearby trees and shrubs can also increase the amount of sunlight reaching the ground, making the area less hospitable for the shade-loving plant.
Adjusting watering habits reduces the weed’s advantage. Watering deeply but infrequently helps the turf develop strong roots while keeping the soil surface drier, which discourages the shallow-rooted Creeping Charlie. For very dense patches, using a thatch rake can help dislodge and remove significant portions of the stolons before follow-up manual removal or environmental changes are implemented.