Grasses with runners form the backbone of many resilient lawns and natural meadows, quietly spreading through intricate underground networks. These specialized stems, known scientifically as rhizomes or stolons, allow a single plant to colonize significant areas over time. Understanding how these botanical runners function reveals the secret to their persistent presence in both managed and wild landscapes. This persistence is a double-edged sword, creating lush coverage while often challenging containment efforts.
The Science Behind Runners in Grasses
The term "runners" describes above-ground stems that grow horizontally along the soil surface, generating new roots and shoots at each node. Below the surface, rhizomes perform a similar function but travel horizontally beneath the topsoil. Both structures store nutrients and enable the plant to survive harsh conditions, pushing up new growth when conditions improve. This vegetative reproduction bypasses the need for seeds, allowing for rapid territory expansion.
Stolons vs. Rhizomes: What’s the Difference?
The primary distinction lies in their position relative to the ground. Stolons, often called "above-ground runners," arch over the surface and root at the nodes where they touch the soil. In contrast, rhizomes develop entirely underground, sending up vertical shoots that become new plants. Bermuda grass is a classic example of a stolon-forming species, while Kentucky bluegrass frequently relies on rhizomes for spreading.
Common Grasses Known for Their Runners
Several popular turf varieties are recognized for their aggressive runner systems. These grasses are valued for their ability to recover quickly from damage and fill in bare patches without reseeding. Homeowners often encounter these species because of their vigorous nature, which requires specific mowing and edging strategies.
Bermuda Grass: Thrives in warm climates and produces both stolons and rhizomes.
Zoysia Grass: Forms a dense mat through aggressive above and below-ground runners.
Buffalo Grass: A durable native species that spreads via rhizomes in cooler regions.
St. Augustine Grass: Relies on above-ground stolons to quickly cover large areas.
Managing Runner Growth in Lawns
While runners create a thick, resilient lawn, they can also lead to encroachment into garden beds or neighboring turf. Containment often requires physical barriers, such as deep edging or buried landscape borders. Regular mowing at the correct height prevents the stems from spreading too far, encouraging the plant to focus energy on vertical growth rather than horizontal expansion.
Controlling Unwanted Spread
For gardeners seeking to limit the territory of a runner grass, consistent edging is essential. Removing the new shoots that emerge beyond the desired boundary prevents the plant from gaining ground. Invasive species, such as Bermuda grass in a fescue lawn, may require targeted herbicides applied directly to the actively growing edges to prevent regrowth.
The Benefits of Runner-Based Grasses
Beyond their persistence, these grasses offer significant advantages for high-traffic areas. Their interconnected root systems create a robust network that prevents soil erosion and tolerates heavy use. Because they propagate naturally, they often require less fertilizer and water than bunch-type grasses that do not spread as readily.
