Creeping plants spread by underground stems or by putting out stems or runners, which root in nearby soil, enabling them to cover large areas. Creeping shade plants make good ground covers on slopes, under trees and in areas where it is difficult to grow grass. Most creeping shade plants offer low-maintenance care and have good disease resistance. Because these plants tend to be vigorous growers, some can become aggressive and even invasive. Always consider the suitability of the plant for a specific site.
Periwinkle (Vinca minor), pachysandra (Pachysandra terminalis) and sweet woodruff (Gallium odoratum) provide evergreen ground cover for shady spots. Periwinkle, also called myrtle, thrives in U.S. Department of Agriculture plant hardiness zones 4 through 9, while pachysandra grows well in zones 5 through 10 and sweet woodruff in zones 4 through 8. Pachysandra makes an elegant, deep green carpet about 10 inches tall in full shade. Plants spread by underground stems and like soil amended with organic material. Periwinkle has small, glossy, oval, dark green leaves and spreading stems that produce roots when touching moist soil. It forms a 4- to 6-inch dense ground cover. In spring, plants are covered with purple, blue or white flowers, depending on variety. Sweet woodruff spreads by underground stems to form a 6- to 12-inch carpet of delicate green leaves, blooming with tiny fragrant, white flowers in late spring. All of these evergreen creeping plants grow well under trees, because they do not compete with tree roots.
Some creeping shade plants are primarily valued for their leaves. Bishop's weed (Aegopodium podgraria) has insignificant flowers, but attractive, deciduous leaves, each made up of three leaflets. The variegated cultivars of Bishop's weed are especially striking in shade and not as aggressive as the green varieties. Bishop's weed grows up to 12 inches high, spreading by underground stems in hardiness zones 4 through 9. Epimedium (Epimedium spp.), also called barrenwort, and creeping Jenny (Lysimachia nummularia) both have pretty flowers, but are typically grown for their distinctive foliage. Epimedium displays delicate, heart-shaped leaves that grow to 3 inches, growing in zones 3 through 9. Creeping Jenny has round leaves and yellow flowers, growing low to the ground and forming new roots wherever nodes on stems touch soil in USDA zones 3 through 8. The variety "Aurea" (Lysimachia nummularia "Aurea") has golden foliage, lighting up shady areas.
Ajuga (Ajuga reptans), also called carpet bugle, lily-of-the-valley (Convallari majalisa) and violets (Viola spp.) are prized for their flowers. Ajuga forms a thick carpet of green, purplish, brown or variegated leaves, depending on variety. In spring and early summer, 6- to 9-inch blue or purple flower spikes appear. Ajuga grows rapidly in sun or deep shade, spreading by runners in hardiness zones 4 through 10. Lily-of-the-valley has upright, green lance-shaped leaves and displays fragrant, white bells in mid-spring in USDA zones 3 through 9. Lily-of-the-valley spreads slowly by underground rhizomes and does not mind competition from tree or shrub roots. Several varieties of violets, such as fragrant sweet violet (Viola odoratum), with attractive heart-shaped leaves, spread by runners. They make good ground covers under trees and shady areas in USDA zones 6 through 10.
Because most creeping shade plants grow under adverse conditions such as low light, they tend to be vigorous and aggressive and can even be invasive. With stems that root as they spread, English ivy (Hedera helix) is one of the most aggressive creepers and climbers. Hardy in zones 4 through 9, it is considered invasive in the Pacific Northwest. However, newer varieties are less aggressive. Bishop's weed and ajuga are moderately aggressive, especially when growing in sun, while periwinkle, sweet woodruff, creeping Jenny and violets are moderate to slightly aggressive. Epimedium and pachysandra are relatively non-aggressive. Aggressive creeping shade plants are good in areas where nothing else will grow, or in areas edged by a barrier such as a driveway, walkway or edging. If you want a perfect lawn, ajuga and violets may not be for you.