Ground cover plants are low-growing species that spread horizontally to form a dense, living layer over the soil. They are widely used where conventional turf grass fails to thrive due to environmental challenges like deep shade, poor soil, or excessive moisture. By choosing a plant adapted to these difficult conditions, gardeners can achieve a low-maintenance landscape that prevents erosion and suppresses weeds. This approach requires understanding the specific demands of the site.
Identifying the Specific Problematic Conditions
Before selecting any plant, diagnose precisely why grass failed in the specific location. The most common limiting factor is light exposure, which should be assessed by counting the hours of direct sunlight the area receives daily. Full sun is defined as six or more hours of direct light, while deep shade receives very little direct light.
Soil conditions also significantly determine a plant’s success, particularly texture, nutrient composition, and drainage capability. To test drainage, dig a hole about 12 inches deep, fill it with water, allow it to drain, and then refill it, timing the second drainage. Well-drained soil should drain at approximately one inch per hour; a slower rate indicates poor drainage or clay-heavy soil, while a faster rate suggests loose, sandy soil.
Assessing the soil’s moisture level and texture is important. Compacted clay soil retains too much water, potentially leading to root rot, while sandy soil drains too quickly and will not hold necessary moisture. Choosing a plant that naturally suits the existing soil and moisture conditions is more effective than attempting continuous soil modification.
Ground Covers for Deep Shade
Deep shade is a frequent cause of turf failure, often occurring under mature trees or on the north side of structures where light is severely limited. Plants suitable for this environment have adapted to photosynthesize efficiently using low levels of filtered or indirect light. Once established, these shade-adapted species reduce the need for maintenance.
One reliable option for deep shade is Vinca minor (common periwinkle), which maintains glossy green foliage year-round. This plant creates a dense mat of growth, typically reaching four to six inches in height, and spreads through trailing stems that root as they creep. Vinca is excellent for areas prone to erosion, as its dense root network stabilizes the soil on slopes under tree canopies.
Ajuga reptans (bugleweed) is another resilient choice for shady spots, known for its attractive dark foliage and colorful flower spikes. Ajuga spreads quickly to form a dense, low carpet, effectively suppressing weeds by blocking light at the soil surface. This ground cover generally stays below six inches in height.
While many Hosta varieties are grown for their dramatic foliage, they can function as a ground cover when planted closely, particularly the smaller types. Hostas provide textural interest and thrive in the low light conditions found in woodland gardens. They form individual clumps that collectively cover the ground, offering a different growth habit than creeping varieties.
Ground Covers for Dry Soil and Slopes
Areas characterized by dry soil, such as sandy compositions or steep slopes, require plants with specialized mechanisms for water conservation and soil stabilization. These drought-tolerant plants possess root systems that firmly anchor the soil, controlling erosion caused by wind and water runoff. Once established, they require minimal supplemental watering, making them ideal for xeriscaping.
Sedum (Stonecrop) varieties, particularly the low-growing mat-forming types, are effective in hot, dry, and sunny locations. These succulents resist drought by storing water within their fleshy leaves and stems, allowing them to withstand weeks without moisture. The ‘Angelina’ variety of Sedum rupestre is notable for its needle-like, chartreuse foliage that provides year-round color in poor, well-drained soil.
Creeping Thyme (Thymus serpyllum) is a fragrant, low-growing perennial that thrives in sunny, dry areas and performs well between stepping stones or along paths. This plant forms a dense, mat-like growth that is resilient and suited to poor, quickly draining soil. Its dense, fibrous roots contribute to soil stabilization on gentle slopes.
For challenging slopes where erosion is a significant concern, the deep roots of plants like Creeping Juniper (Juniperus horizontalis) or Moss Phlox (Phlox subulata) are beneficial. Moss Phlox, a fast-growing, semi-evergreen plant, forms a dense mat with roots that stabilize hillsides and bluffs. These woody or semi-woody species handle heat and wind better than softer growth and help unify the soil structure.
Ground Covers for Foot Traffic and Moist Areas
Some locations demand ground covers capable of handling occasional walking or those adapted to consistently moist soil conditions. These specialized plants provide solutions for walkways, stepping stone pathways, and areas near downspouts or water features. The ability to tolerate foot traffic usually comes from a low, mat-forming habit and the capacity to root along stems.
For areas that experience light to moderate foot traffic, Mazus reptans is an excellent choice due to its dense, mat-forming growth habit and resilience. This perennial grows only a few inches high and spreads by creeping stems that root at the nodes, allowing it to withstand occasional walking. Mazus prefers moist, rich, well-drained soil, but it is not drought-tolerant and requires consistent moisture.
Another moisture-tolerant option is Creeping Jenny (Lysimachia nummularia), valued for its bright, chartreuse foliage and ability to thrive in damp areas. This plant prefers moist, fertile soil and is often used near ponds or streams where the soil remains consistently wet. Creeping Jenny exhibits moderate to high tolerance for foot traffic.
For pathways between pavers where a very low profile is needed, Irish Moss (Sagina subulata) or low-growing Chamomile are often used. Irish Moss forms a tight, velvety cushion that can be walked on and thrives in moist, well-drained soil. Their ability to withstand compression makes them suitable for use as a living grout between stones.
Preparing the Site and Planting
Successful establishment of ground cover begins with thorough site preparation. The most important initial step is the complete elimination of existing weeds, grass, and turf, which will otherwise compete aggressively with the new plants. This can be achieved either by manually removing the vegetation or by using a smothering technique with materials like black plastic or cardboard.
For flat areas, the soil should be loosened to a depth of about six inches, often by tilling, to improve aeration and root penetration. Tilling should be avoided on steep slopes because loose soil increases the risk of erosion. Amending the soil with organic matter, such as compost, can improve both drainage in clay soil and moisture retention in sandy soil.
When planting, ground cover plants should be spaced according to their predicted mature spread to achieve full coverage without overcrowding. Planting too few plants leaves gaps where weeds can germinate, while planting too closely can lead to poor air circulation and disease. A common spacing for many creeping varieties is 8 to 12 inches apart, allowing the plants to fill in over one or two seasons.
After the plants are set into the ground, they must be watered thoroughly to settle the soil around the roots and eliminate air pockets. During the first two months, the ground cover requires consistent moisture to establish its root system; a single deep soaking is more beneficial than frequent light sprinklings. Applying a layer of mulch after installation helps to suppress new weeds and conserve soil moisture.