Buffalo grass (Bouteloua dactyloides) is a warm-season turfgrass native to the North American Great Plains, prized for its low-maintenance profile and exceptional drought tolerance. It is a sod-forming grass, meaning it actively spreads horizontally to create a dense turf cover. This lateral growth is how the grass fills in bare spots and establishes a continuous lawn surface after planting.
The Primary Mechanism: Spreading via Stolons
Buffalo grass achieves its lateral spread exclusively through specialized above-ground stems called stolons. These stolons, often referred to as runners, grow along the surface of the soil, extending outward from the main plant. At various points along the runner, called nodes, the stolon can produce new roots that anchor the stem and new shoots that grow vertically, forming a daughter plant.
This mechanism differs significantly from the growth habit of many other turfgrasses. Some aggressive grasses, such as Kentucky Bluegrass and Bermuda grass, spread using underground stems called rhizomes, in addition to or instead of stolons. Unlike rhizomes, which can grow deep into the soil and are protected from surface damage, the stolons of Buffalo grass are fully exposed.
This surface-level growth makes Buffalo grass easier to contain. It relies entirely on surface runners to colonize new areas and repair damage. The stolon-only spreading habit contributes to Buffalo grass’s lower overall invasiveness compared to grasses that utilize both stolons and rhizomes.
Factors Determining Spread Rate and Density
The rate at which Buffalo grass spreads and the ultimate density of the turf depend heavily on environmental conditions and cultural practices. Under ideal conditions, a Buffalo grass lawn planted from seed at a high rate can achieve complete coverage within a single growing season. When planted from plugs, the time to full coverage can range from six to twelve months, depending on the spacing of the plugs and the encouragement of lateral growth.
Sunlight is a major determinant of spread, as Buffalo grass requires full sun, typically six to eight hours of direct light daily, for optimal growth. Areas with partial shade will result in noticeably thinner stands, and the lateral spread of stolons will be significantly slower in these lower-light conditions. The soil type also plays a role, with well-drained loam being the preferred medium for rapid establishment. While the grass can tolerate heavy clay, establishment is slower on compacted or poorly drained sites because the stolons struggle to root effectively.
Water availability and fertilization practices also directly influence the speed of colonization. During the establishment phase, consistent moisture is necessary to support the vigorous production of stolons and new roots. Mowing height directly affects density, as maintaining a taller height—around two to three inches—encourages stronger stolon development and a denser canopy.
Actionable Steps for Managing Lateral Growth
Managing Buffalo grass involves either intentionally speeding up the spread for establishment or containing it to prevent unwanted growth. To encourage rapid establishment, particularly when planting from plugs or a lower seeding rate, strategic fertilization is beneficial. Applying a slow-release nitrogen fertilizer in the early summer, when stolon production begins, provides the necessary nutrients to fuel lateral growth.
Aerating the soil is another technique to accelerate spread, as it relieves compaction and promotes better movement of water and oxygen to the root zone. This is especially helpful in clay soils where stolon rooting can be inhibited by hard ground. Maintaining consistent moisture during the first year helps ensure the stolons can successfully anchor themselves and form new plants.
For containment, the above-ground nature of the stolons simplifies the process compared to grasses with deep rhizomes. Physical barriers, such as edging installed along flower beds or walkways, are highly effective at stopping the runners. The stolons will simply run up to the barrier, making it easy to see and trim any stray runners that attempt to cross. Regular monitoring and trimming of the visible runners prevents the plant from colonizing adjacent non-turf areas.