The genus Veronica, commonly known as speedwell, is a widespread group of low-growing plants found across nearly every temperate region of the world. Homeowners and gardeners often debate whether this herb is a welcome sign of spring or a persistent lawn invader. The answer depends entirely on the specific species and the environment in which it is growing. Speedwell’s prolific nature and ability to thrive in poor conditions have established it as a highly successful plant, regardless of whether it is viewed as a decorative wildflower or an unwelcome weed.
Identifying Common Speedwell Species
Identifying the specific type of speedwell is the first step toward managing it, as the genus includes hundreds of species with varied growth habits. Most weedy varieties are characterized by small, four-petaled flowers, typically bright blue, violet, or white, which bloom prolifically in spring. The flowers are often distinctly lobed, with the upper petal appearing slightly larger than the others.
The leaves are generally oval-to-rounded with scalloped or toothed edges and are arranged oppositely along the creeping stems. Common lawn species include the winter annual Persian Speedwell (Veronica persica), which has relatively large blue flowers and heart-shaped seed pods. The perennial Creeping Speedwell (Veronica filiformis) is known for its slender stems that root easily at the nodes. Corn Speedwell (Veronica arvensis) is another widespread annual, identifiable by its small flowers that are nearly hidden by the sepals. These low-growing habits allow the plant to escape standard lawnmower blades and spread unchecked beneath the turf canopy.
The Dual Identity of Speedwell
The classification of speedwell is entirely contextual and determined by the environment it inhabits. In a maintained lawn, speedwell is considered a nuisance plant due to its vigorous, mat-forming growth. Creeping varieties spread aggressively by sending out stems that root wherever they touch the soil, quickly suffocating desirable turfgrass.
This aggressive competition is compounded by the plant’s tolerance for conditions that weaken grass, such as compacted soil, low fertility, and excessively moist areas. Its low profile allows it to survive regular mowing, establishing a dense, persistent carpet within the turf. Conversely, in non-lawn settings, speedwell is often viewed as a beneficial plant or a charming wildflower.
Historically, species like Veronica officinalis were used in folk medicine, sometimes brewed as “Poor Man’s Tea.” Modern ecological gardens value the plant as a natural groundcover that helps control erosion in difficult areas. Furthermore, its small, early-blooming flowers are an important source of nectar for pollinators in early spring when other food sources may be scarce.
Effective Control and Eradication Methods
Eradicating speedwell from a lawn requires a combined strategy of cultural adjustments, manual removal, and targeted chemical control. The most effective long-term method is cultural control, which focuses on maintaining a dense, healthy turf that naturally crowds out weed seedlings. This involves raising the mowing height to encourage taller, thicker grass blades, reducing the sunlight reaching the low-growing speedwell.
Proper soil management, including aeration to relieve compaction and appropriate high-nitrogen fertilization, promotes vigorous turf growth that restricts the weed’s ability to establish. When dealing with small, isolated patches, manual removal is a viable option, but it requires persistence. The fibrous root systems and creeping stems must be completely removed, especially those that have rooted at the nodes, to prevent regeneration.
For widespread infestations, chemical control is often necessary, but speedwell can be resistant to many common broadleaf herbicides. Post-emergent products containing a combination of active ingredients, such as triclopyr and dicamba, are recommended for better efficacy. The timing of application is crucial, with the best results occurring in the fall or early spring when the plant is actively growing and can effectively absorb the chemical. For annual species, applying a pre-emergent herbicide in the late winter or early spring can significantly reduce the number of germinating seeds, offering a proactive management solution.