Ground cover in gardening refers to any plant material used to form a dense, low-growing layer over the soil surface, serving as a functional and aesthetic alternative to traditional turfgrass or mulch. This living layer is a foundational element in sustainable landscape design, offering solutions for areas where other plants struggle. The primary goal of a ground cover planting is to completely conceal the bare earth, creating a uniform, continuous expanse of foliage.
What Exactly is Ground Cover
Ground cover is defined as any plant, typically perennial, that exhibits a creeping, spreading, or mat-forming growth habit to quickly and uniformly colonize a given area of ground. These plants are characterized by their low profile, generally growing from a few inches up to about 18 inches in height, though some may reach four feet. The ability to spread laterally, often through runners, rhizomes, or rooting stems, is what distinguishes them from upright perennials or shrubs.
The dense canopy and interconnected root systems of ground cover plants create a living barrier over the soil that requires minimal long-term care. While turfgrass is technically a ground cover, the term is applied to species that thrive where traditional lawns fail, such as deep shade or on steep slopes. An ideal ground cover is durable, relatively fast-growing, and tough enough to withstand challenging environmental conditions once established.
Essential Roles in Ecosystem and Gardening
Ground covers serve multiple functions that contribute to both garden health and broader ecological balance, beginning with effective weed management. Once a dense mat of foliage is established, the ground cover outcompetes unwanted weeds for light, water, and nutrients. The thick, continuous canopy shades the soil surface, preventing weed seeds from receiving the sunlight necessary for germination.
Control of soil erosion is essential, particularly on steep banks or sloped areas. The extensive, fibrous root systems of these plants bind soil particles together, forming a stabilizing network. This root structure minimizes the impact of heavy rainfall and wind, preventing the detachment and transport of valuable topsoil.
Ground covers also play a major role in regulating soil moisture and temperature. By shading the soil, the foliage acts as a natural mulch, reducing the rate of water evaporation from the surface and conserving soil moisture. This reduces the need for frequent irrigation, benefiting drought-prone regions. Furthermore, the decomposition of fallen leaves and stems adds organic matter, which enhances soil structure and fertility over time.
Choosing the Right Ground Cover for Your Needs
Selecting the appropriate ground cover requires matching the plant’s specific needs to the site’s environmental conditions. The amount of light exposure is a primary factor, dividing plants into those that need full sun—typically six or more hours of direct light—and those that prefer partial or full shade. Plants thriving in deep shade, such as Vinca minor (Periwinkle), are often used beneath trees where turfgrass struggles due to lack of light and root competition.
Soil characteristics, including type, drainage, and pH level, heavily influence the success of the planting. For instance, succulents like Sedum varieties are excellent choices for dry, well-drained soils in hot, sunny locations. Conversely, plants suitable for damp or poorly drained areas must be selected specifically for moisture tolerance. The plant’s hardiness zone must also be considered to ensure it can survive the local climate and winter temperatures.
Beyond environmental factors, the desired outcome dictates the choice of ground cover type. For year-round color, evergreen varieties are preferred, while flowering types, like Creeping Phlox (Phlox subulata), provide seasonal blooms. When selecting a spreading variety, choose one that fills in quickly but is not overly aggressive or invasive, avoiding species that require constant maintenance.
Planting and Maintaining Ground Cover
Successful establishment of ground cover begins with thorough site preparation, as these plants are often intended to remain in place for many years. The planting area should be cleared of all existing weeds, especially aggressive perennial types, since young ground cover plants cannot compete effectively against them. Soil quality is improved by incorporating organic matter, such as compost or well-rotted manure, to a depth of six to ten inches to enhance drainage and nutrient retention.
The most effective planting technique is a staggered pattern, which encourages the quickest and most uniform coverage of the area. Proper spacing is an important consideration; planting too far apart leaves open areas for weeds, while planting too close unnecessarily increases cost. After planting, a light layer of organic mulch, such as shredded bark, helps to suppress weeds and retain soil moisture during the establishment phase.
Initial care focuses on consistent moisture until the root systems are fully developed, which can take up to two years. While most ground covers are low-maintenance once established, some may benefit from a light application of a slow-release, balanced fertilizer a few times during the first growing season to encourage vigorous spread. Long-term maintenance generally involves minimal pruning to control spread and occasional thinning or dividing to rejuvenate older, less vigorous patches.