A perennial ground cover is a low-growing plant that acts as blanket for the landscape. Grass remains the most widely used ground cover because it withstands foot traffic and protects the soil. But grass does not work in every situation. In instances where grass proves difficult to grow and mow, a ground cover like creeping thyme serves as a beneficial alternative.
Traditionally, gardeners used a perennial ground cover to prevent erosion and fix problem areas like shaded slopes. Now a ground cover functions as a container plant and as filler between shrubs or flower bed edging. Ground cover adds color, pattern and texture to the landscape. For instance, lamb's wool brings interest to a planting scheme with it soft, silver, woolly foliage. Ground cover also defines and unifies space. A plant like rupturewort works well between concrete pavers to link a lawn to a patio space.
Ground cover possesses advantages, such as reduced maintenance. It requires less fertilizer, irrigation and mowing than grass. The plant's decaying foliage adds organic matter to the soil, and it acts as a mulch that retains moisture and prevents weeds. Ground cover attracts wildlife. For example, sedum draws butterflies, and hosta flower heads attract hummingbirds. Ground cover helps reduce foot traffic in some situations. For instance, the West Virginia Cooperative Extension says people avoid crossing ground cover more than 4 feet wide.
Select a type of ground cover to suit the climate. A perennial ground cover behaves like an annual in northern climates if it is not cold hardy. Match the ground cover to the site. Consider the amount of light the planting site receives and the drainage, pH and texture of the soil. Think about the location of the planting site. A slope requires a plant with a strong root system like evening primrose. A street-side site needs a ground cover that can withstand foot traffic and regenerate quickly, such as creeping juniper.
Perennial ground covers demonstrate a variety of habits and shapes. An evergreen ground cover, such as wintergreen cotoneaster, retains color throughout the year. A deciduous ground cover, such as cranberry cotoneaster, dies back or sheds foliage at the end of the growing season. A ground cover like periwinkle emerges in clumps, while creeping lily turf forms a dense mat. Ornamental grass, a shrub and a trailing vine also qualify as a ground cover.
Ground cover possesses a spreading habit by nature, but the plant becomes invasive when it creeps, self-seeds and crowds out native vegetation. Bugleweed jumps boundaries, and wintercreeper likes to climb trees. Even small root sections of bishops' weed tend to re-emerge and spread aggressively. Select a native ground cover, such as the crested iris or Alleghany pachysandra when possible. Plant ground cover in contained beds or use edging to control the spread. Cut back all escaping plants.