Creeping speedwell (Veronica filiformis) is a low-growing perennial often found as a weed in lawns and gardens. While its delicate flowers can be visually appealing, this plant is an aggressive, invasive weed that quickly overwhelms desired vegetation. This article guides identifying creeping speedwell, understanding its invasive nature, and implementing effective control and management strategies.
Identifying Creeping Speedwell
Identifying creeping speedwell involves recognizing its distinct physical attributes. This perennial forms low-growing, mat-like patches with slender, creeping stems up to 50 cm long. These stems readily root at their nodes wherever they touch the soil, contributing to rapid spread. Its small leaves (typically 5-12 mm across) are rounded or kidney-shaped with scalloped or bluntly toothed edges. They are often hairy and arranged oppositely on lower stems, becoming alternate on flowering stems.
Its small, delicate flowers are a notable identifying feature. These four-petaled flowers are usually light blue to purple with darker veins and a white center, about 8-10 mm in diameter. Each flower appears singly on long stalks from leaf axils. Flowering typically occurs from early spring into early summer, creating a carpet-like appearance.
Understanding Its Invasive Nature
Creeping speedwell is invasive due to its aggressive growth and efficient reproduction. It spreads rapidly through creeping stems (stolons) that root at every node, forming dense mats that smother turfgrass and other garden plants. This plant outcompetes desirable vegetation for water, nutrients, and sunlight. Its ability to thrive in various conditions, particularly moist, shady, and nutrient-rich soils, makes it a persistent problem.
The plant reproduces from small stem fragments; even pieces scattered by mowing equipment can root and establish new plants, leading to widespread infestations. While it rarely produces viable seeds, its vegetative spread is highly effective. This aggressive growth impacts lawn aesthetics, compromises garden plant health by reducing resource access, and can displace native plant communities.
Effective Control Strategies
Controlling creeping speedwell infestations requires a multi-faceted approach: manual, cultural, and, when necessary, chemical methods. For smaller infestations, manual removal is effective. Hand-pulling is feasible, but remove all root fragments and stems, as the plant re-grows from small pieces. Use a hand fork or trowel to loosen soil for thorough removal of its shallow fibrous root system. Discard removed plant material carefully to prevent further spread.
Cultural practices significantly reduce speedwell. Promoting a healthy, dense lawn or garden naturally outcompetes the weed. Maintain proper mowing heights, as taller grass shades out speedwell. Adequate watering and appropriate fertilization contribute to robust turf less susceptible to weed invasion. In garden beds, a thick layer of organic mulch, such as bark chips, suppresses new growth by blocking light and creating a physical barrier.
For extensive infestations, chemical control may be necessary. Selective broadleaf herbicides are effective against creeping speedwell without harming turfgrass. Look for products with active ingredients like dicamba, triclopyr, 2,4-D, or fluroxypyr. Apply in fall or early spring when the plant is actively growing and can readily absorb the herbicide. Apply on a calm day with no rain for at least 24 hours, and always follow product instructions for safe and effective application, noting that hairy leaves can resist uptake.
Long-Term Management and Prevention
Sustaining a landscape free from creeping speedwell involves consistent long-term management and preventative measures. Regularly monitor for new growth, allowing prompt action before it establishes widely. Improving soil health favors desired plants over weeds. Ensure proper drainage and aeration through practices like core aeration and amending soil with organic matter.
Choose appropriate plants for your site conditions to help them thrive and outcompete weeds. Select turfgrass varieties well-suited to your climate and soil type to encourage a dense, vigorous lawn. Maintain proper garden and lawn routines, such as consistent watering and fertilization, to ensure overall health of desired vegetation, making it more resilient to weed pressure. Regularly clean gardening tools and equipment, especially after working in infested areas, to prevent inadvertent spread of speedwell fragments.