A ground cover is a low-growing plant used intentionally to cover the soil surface. They offer an alternative to turfgrass, which often fails to thrive in areas deprived of adequate sunlight. Ground covers are particularly beneficial in shaded yards, where they prevent soil erosion, suppress weed growth, and add texture and visual interest to otherwise bare ground. Selecting the correct variety for a specific location is paramount, as the environment beneath a tree canopy presents unique challenges to plant survival. This article provides specific solutions for selecting and establishing ground covers suited for the diverse conditions found in shaded yards.
Understanding Types of Shade
Successfully choosing a shade-tolerant ground cover begins with accurately assessing the light and moisture conditions present in the area. Light levels are generally categorized by the amount of direct sun exposure the space receives during the day. This assessment is the single most important factor for determining plant viability.
Deep or full shade refers to areas that receive fewer than two hours of direct sunlight, often filtered or entirely blocked by dense tree canopies or the north side of a structure. Plant selection for this environment focuses on species that can photosynthesize efficiently using only ambient light. Partial or dappled shade, conversely, involves two to four hours of direct morning sun or consistent light filtering through leaves throughout the day.
Moisture availability further refines the selection process, creating the challenging category known as dry shade. This condition typically occurs beneath mature trees, where extensive root systems aggressively absorb soil moisture. Plants selected for dry shade must be tolerant of high root competition, while areas with partial and moist shade allow for a greater variety of plant forms and colors.
Ground Covers for Deep and Dry Shade
The most challenging environments, characterized by minimal light and intense moisture competition, require ground covers with extreme resilience. Japanese Pachysandra (Pachysandra terminalis) is a classic choice, forming a dense, evergreen carpet that effectively suppresses weeds. This species is particularly useful under trees, as it tolerates the acidic soil often found in such locations.
Another highly tolerant selection is barrenwort, or Epimedium, which is semi-evergreen and produces delicate, columbine-like flowers in the spring. While it spreads slowly, Epimedium is remarkably successful in dry, shaded conditions once its roots are established.
Sweet Woodruff (Galium odoratum) is an aromatic, semi-evergreen plant known for its whorls of bright green leaves and clouds of tiny white flowers in spring. It is often used to carpet steep, shaded banks.
Mondo grass (Ophiopogon japonicus) provides a low-growing, fine-textured alternative to turfgrass in most shady areas. This evergreen perennial forms dense, blade-like clumps that reach only three to four inches in height. It is particularly effective for covering exposed tree roots or helping to stabilize soil on slopes.
Ground Covers for Partial and Moist Shade
When light levels are slightly higher or soil moisture is consistently available, gardeners can choose from a wider palette of textures and colors. Hosta varieties are effective ground covers, with hundreds of cultivars offering variety in leaf color, texture, and size. The large leaves quickly expand to shade the ground, which helps to inhibit weed germination.
Periwinkle (Vinca minor) is an evergreen perennial that excels in partial to full shade, creating a dense mat of glossy dark green leaves. It produces white or lilac-blue flowers that appear in the spring. Although Vinca is adaptable, it performs poorly in overly wet sites.
Bugleweed (Ajuga reptans) is a low-growing, spreading plant that develops into a dense cover. While the flowers are typically violet-blue, many cultivars are selected for their colorful foliage, which includes combinations of bronze, purple, and burgundy. Ajuga performs best in partial shade with well-drained soil.
Spotted Deadnettle (Lamium maculatum) is another colorful choice, featuring silvery-variegated leaves that brighten shady corners. It is valued for its attractive foliage and pink, purple, or white flowers that bloom from late spring into summer. Ferns, such as the Maidenhair fern (Adiantum pedatum), also offer soft, feathery textures and thrive in consistently moist, shaded conditions.
Installation and Long-Term Care
Site Preparation
Proper site preparation is essential for the long-term success of any ground cover planting, as these perennials are intended to remain in the same location for many years. The soil should be worked to a depth of eight to ten inches to relieve compaction and allow for robust root development. Incorporating a two-inch layer of organic matter, such as compost or well-rotted manure, improves drainage in heavy clay soils and increases the water-holding capacity of sandy soils.
Planting Technique
Planting technique involves strategic spacing. Setting plants too far apart prolongs the time until full coverage is achieved and increases the need for weeding, while planting too closely wastes material. A staggered-row pattern is generally recommended to encourage the quickest, most uniform spread.
Establishment and Watering
During the initial establishment phase, which can take up to two years, consistent watering is required, even for species that are ultimately drought-tolerant. Newly planted ground covers must be kept consistently moist to encourage the development of a strong root system. Applying a two-inch layer of mulch after planting helps suppress weeds and retains soil moisture.
Managing Spread
Certain vigorous species, including Vinca and Ajuga, may spread aggressively, requiring management to prevent them from encroaching on neighboring beds. This control can be maintained through regular pruning of the runners or the installation of a physical barrier, such as garden edging. Inspection for weeds should be performed until the plant canopy is completely closed, as established ground covers will then effectively outcompete most unwanted growth.