Creeping Jenny (Lysimachia nummularia) is a popular groundcover plant prized for its dense, bright foliage. For gardeners wondering if this plant will reappear each spring, the answer is a definitive yes. This species is classified as a hardy perennial, meaning it reliably returns year after year. Its vigorous growth habit makes it a favorite for quickly filling empty spaces, but this persistence is also what makes it a challenge for some.
The Perennial Nature of Creeping Jenny
The ability of Creeping Jenny to return is rooted in its biological classification as an herbaceous perennial. It possesses a robust, underground root system that remains dormant but alive through the winter months, allowing the plant to survive freezing temperatures and harsh conditions. This plant exhibits impressive cold tolerance, thriving across USDA hardiness zones 3 through 9. While the foliage may remain semi-evergreen in milder regions, the above-ground growth typically dies back in colder zones, entering a strategic winter dormancy where the plant conserves energy in its roots and crowns. This stored energy ensures that the plant initiates vigorous new growth the moment temperatures become favorable in the spring.
Mechanisms of Spreading and Regrowth
Creeping Jenny’s aggressive return is not solely due to its perennial nature but also its highly effective vegetative spreading mechanisms. The plant’s primary method of expansion is through creeping stems, often called runners, which trail horizontally across the soil surface and root rapidly at the leaf nodes wherever they make firm contact with moist earth. Once a node roots, it establishes a new, independent plantlet that is genetically identical to the parent, forming a dense, interlocking mat; even the popular golden cultivar, Lysimachia nummularia ‘Aurea’, employs this vigorous rooting strategy. Another factor contributing to its persistent regrowth is fragmentation, as the somewhat brittle stems easily break off during manual weeding or soil disturbance. Each tiny segment of stem that contains a node has the potential to sprout roots and establish a new plant, making complete manual removal extremely difficult.
Managing Aggressive Return
For gardeners who find Creeping Jenny’s vigorous spread overwhelming, the first strategy involves containment and physical removal. Planting the species in containers, hanging baskets, or raised beds prevents its runners from making contact with the surrounding garden soil, and using physical borders, such as deep-set metal or plastic edging, can also restrict the plant’s spread. When manual removal is necessary, it must be thorough: the plant is relatively shallow-rooted, but it is important to remove the entirety of the root system and all stem fragments. Using a flat spade or trowel to scoop just below the surface helps ensure that the entire mat, including the numerous rooted nodes, is lifted out. For large infestations, chemical intervention may become the most practical option, using targeted broadleaf herbicides like glyphosate or triclopyr, which are most effective when applied in the early spring or fall to allow the chemical to be transported down to the root system.