Ground Covers

                                                                                                                            Publication 471
Also available in PDF form at http://www.wvu.edu/~agexten/turf/grndcov.pdf
Clifford W. Collier, Jr., Extension Specialist, Landscape Architecture
George W. Longenecker, Professor, Landscape Architecture
Revised by John Jett, Extension Specialist, Horticulture

Nature used ground covers as earth carpets long before man conceived the idea of using evergreen vines and low growing shrubs as labor saving devices. Today’s way of life has brought an even greater demand for ground cover plants and more emphasis is placed on their esthetic qualities as well as the functions they serve.

This increased demand has brought about the development of new cultivars of plants which possess varied esthetic qualities, such as a variety of flower color, size and color of foliage and habit of growth. Low growing shrubs, which reach a height of three feet or less are often utilized. Also, some annuals and perennials have found special uses as ground covers.

Herbaceous plants are often overlooked as ground covers because generally a year-round effect is desired. The root systems of these plants still aid in holding the soil during the winter and they produce more blooms with a greater variety of color than is found in most woody plants. Herbaceous plants are especially effective in areas covered by snow most of the winter months, around summer homes, resorts and recreation areas or even along roadsides.

Landscaping with Ground Covers

Once, the sole purpose of ground covers was to act as a substitute for grass and they were used to stabilize the soil and prevent erosion on banks too steep to mow. They were also used to cover bare areas where grass would not grow, such as in heavily shaded areas. Today, ground covers serve many other purposes and their selection should receive the same careful consideration as when selecting other plants to be used in the landscape.

In addition to serving as a substitute for grass, ground covers are used as labor saving devices. Ground covers planted in shrub borders serve as a living mulch – aiding in retaining moisture and eliminating weeds. At the same time they act as a soil conditioner by adding organic matter to the soil through decaying stems and foliage.

Ground covers may also be used to direct traffic. It has been found that people do not cross beds of ground covers that are 4 feet or more wide. Low growing shrubs with prickly foliage, such as junipers, serve the same purpose.

Esthetically, ground cover plants make a great contribution by adding interest to the landscape through changes in forms, textures, colors and sizes; they may serve as a unifying agent for the design; they may make uneven, open areas appear more smooth and level; they may be combined with trees, shrubs, bulbs, and perennials for varying seasonal effects, and they may be used to define areas and establish boundaries.

These are only a few uses of ground covers and with careful consideration, their physical characteristics and esthetic qualities may be used to the fullest advantage.

Selecting Ground Covers

The selection of the proper ground cover is essential if the demands of the situation are to be met and a pleasing picture is to result. Some plants are more suited to some locations and situations than other plants. For example, fine textured plants are more suited to small areas than coarse textured plants. Also, some plants require full sunlight—others prefer shade. Rich loamy soils are required for the cultivation of most ground covers but a few grow best in sandy, dry soils.

The hardiness of the plants is a determining factor in making the right selection. Some plants can withstand sub-zero temperatures while others thrive only in warmer climates. Most of West Virginia lies in zones 4, 5, and 6 as determined by "Plant Hardiness Zone Map," published by the United States Department of Agriculture. These zones in WV have an average minimum temperature which would range from 0F to -30F.

The horticultural requirements of plants are another consideration. Plants such as Partridge berry grow best in high altitudes, in shaded areas, with soils rich in organic matter. On the other hand, Sedum thrives in full sun, in soils that are dry and poor in nutrients.

Planting Ground Covers

In Beds: Plants of a viney nature should be planted in beds which have been prepared in the same manner as for flowers or lawns. The topsoil should be removed and the subsoil cultivated to a depth of six to eight inches. Lime (if needed), fertilizer and a two inch layer of organic matter should be incorporated into the subsoil. Replace the topsoil and repeat the procedure. A rule of thumb is to incorporate five pounds of 20% super-phosphate into the subsoil for every 100 square feet of bed. A complete fertilizer such as 10-10-10 should be added to the top of the soil at the rate of two pounds per 100 square feet of bed.

On Slopes: The degree of slope will determine if a regular bed or individual pockets should be prepared. If individual pockets are dug, make certain they are sufficiently large to accommodate the plant and a backfill of good top soil. A mulch or netting of some description may be necessary to control erosion until the plants become established.

Planting shrubs: Small or dwarf shrubs should be planted in the same manner as other shrubs.

Maintenance of Ground Covers

Ground covers are often considered as "cure alls." This is a definite misconception. Ground covers, though they do require less maintenance than grasses, are living plants and require a certain amount of attention.

Fertilizing: Viney type ground covers, such as ivy, which have a low habit of growth may be fertilized by broadcasting a commercial fertilizer over the area. Then water well to make certain the fertilizer does not adhere to the foliage and burn the plant. Ground covers which have an upright habit of growth, such as Pachysandra, may be fertilized with well rotted manure. The foliage is sufficiently high from the ground so that it will not be burned by the fertilizer. Shrubs should be fertilized in the same manner as other shrubs.

Watering: Ground covers should be watered with sprinklers in the same manner as lawns, or the garden hose may be placed in the bed and allowed to run slowly for several hours. Daily sprinklings can cause the root system to form on the surface of the ground, leaving the plant susceptible to drought. Watering in the evening is not a good idea because the plants do not have sufficient time to dry before dark, thus creating conditions favorable to the growth of fungus.

Weeding: Weeding ground covers can be a tedious operation because it must be done by hand. Herbicides which kill weeds will also affect ground covers. In some instances pre-emergence herbicides may be used to control weed seeds. Consult your local garden center operator, nurseryman or county extension agent for latest recommendations.

Insects and Diseases: Ground covers are subject to attack from insects and diseases the same as all other living plants. Therefore, a good spray program should be established and followed. Again contact a local authority for the best control methods and materials to use.

Ground Cover

Type

USDA
Hardiness Zone**

Size

Remarks

Aegopodium podograria
Bishops Goutweed
Herb 4 6" - 14" May become a weed; poor soils; sun or shade
Ajuga reptans
Carpet Bugle
(Bugleweed)
Herb 5 4" - 12" Evergreen in warm climates; may become a weed; good flower display; moist soil; sun or shade; 12"-18" spacing
Akebia quinata
Fiveleaf Akebia
Vine 5 30’ - 40’ Twining vine, may smother small trees and shrubs; 6’ - 10’ a year; shade or sun
Andromeda polifolia
Bogrosemary Andromeda
Shrub 3 1’ - 2’ Wet, peaty soil; varieties nana and nana compacta lowest in height; spacing 1’
Artemisia stelleriana
Beach Wormwood
(Dusty Miller)
Sub-shrub 3 2’ Dwarf forms available; foliage plant; good for small areas
ArctostaphyIos uva-ursi
Bearberry

(Kinnikinnick)
Shrub 3 6"-12" Dry, sandy, poor soil; spread 15’; 1 gal. size plants; spacing 3’, because of slow growth
Calluna vulgaris
Scotch Heather
Shrub 5 4" - 24" Acid, moist infertile soil; prune severely in late winter; evergreen; many cultivars
Ceanothus americanus
Jerseytea Ceanothus
Shrub 5 3’ Difficult to transplant; dry soil; sun to partial shade
Cerastium tomentosum
Snow-in-summer
Herb 3 3 "-6" Rapid grower; evergreen
Chaenomeles japonica alpina
Alpine Japanese Flowering -quince
Shrub 5 1’ Dwarf; suckers rapidly; sun; 18"-24" spacing
Comptonia peregrina
Sweetfern
Shrub 3 4’ Good for roadsides; acid, moist or dry soil; difficult to transplant
Convallaria majalis
Lily-of-the-Valley
Herb 3 8" Fragrant; divide periodically; good flower display; poor soil; shade or sun; 6" spacing
Cornus canadensis
Bunchberry Dogwood
Shrub 4 9" Sun or partial shade
Coronilla varia
Crownvetch Coronilla
Herb 4 1’ - 2’ Roadsides & steep banks; requires a few years to establish; spreads faster up a bank than down; (seed or crowns)
Cotoneaster adpressa
Creeping Cotoneaster
Shrub 5 1’ - 2’ Cotoneaster have problems with red spider, fire blight and lace bugs; sun; rock gardens Can spread 15’; evergreen
Cotoneaster apiculata
Cranberry Cotoneaster
Shrub 5 1’ - 1’ Cotoneaster have problems with red spider, fire blight and lace bugs; sun; rock gardens Can spread 15’; evergreen
Cotoneaster horizontalis
Rock Cotoneaster
Shrub 5 1’ - 3’ Cotoneaster have problems with red spider, fire blight and lace bugs; sun; rock gardens Can spread 15’; evergreen
Cotoneaster microphylla
Rockspray Cotoneaster
Shrub 6 6" - 12" Cotoneaster have problems with red spider, fire blight and lace bugs; sun; rock gardens Can spread 10’; evergreen
Cytisus beani
Beans Broom
Shrub 6 18" Poor soils, two to three times broader than tall. hybrid; evergreen; sun; 18" spacing
Cytisus procumbens
Ground Broom
Shrub 6 18" Twigs green all winter; transplant small plants; 18" spacing
Cytisus purpureus
Purple Broom
Shrub 6 18" - 24" Shear after flowering; poor soil
Diervilla Ionicera
Dwarf Bushhoneysuckle
Shrub 4 3’ Wasteland and dry banks; sun to partial shade
Diervilla sessilifolia
Southern Bushhoneysuckle
Shrub 5 4’ Not as good as D. Ionicera; wasteland and dry banks
Euonymus fortunei (Var.)
Wintercreeper Euonymus
Shrub-Vine 6 2" - 6" Roots easily at nodes; ever-green; sun; 18" spacing; gets scale
Euonymus obovatus
Running Euonymus
Vine 4 12" Partial shade; 18" spacing; gets scale
Forsythia ‘Arnold Dwarf’ Shrub 6 3’ Flowers greenish-yellow, poor; sun; 2’ spacing
Forsythia viridissima
bronxensis
Bronx Forsythia
Shrub 6 18" Flowers profusely; sun; 18" spacing
Gaylussacia brachycera
Box Huckleberry
Shrub 6 18" Native to West Virginia; ever-green; shade; acid, moist soil; 9" - 18" spacing
Hedera helix (Var.)
English Ivy
Vine 6 6" - 8" Variety ‘Baltica’ used in West Virginia; 4’ - 8’ a year; evergreen; sun or shade; 9"-18" spacing
Hemerocallis (spp)
Daylily
Herb 4 3' Almost any soil; 18" spacing
Hosta (spp.)
Plantainlily, (Funkia)
(August Lily)
Herb 4 1' - 2' Moist or dry soil; semi-shade; 18" spacing
Hydrangea petiolaris
Climbing Hydrangea
Vine-shrub 5 2' Slow in starting; sun or shade
Hypericum buckleyi
Blueridge St. Johnswort
Shrub 6 10" Sandy soil; sun; 2’ spacing
Iberis sempervirens
Evergreen Candytuft
Sub-shrub 5 9" - 12" Rock wall garden; evergreen; sun; 9" - 12" spacing
Ilex crenata (Var.)
Japanese Holly
Shrub 6 3' Special uses, good for small areas; varieties ‘Stokes’ and ‘Heller’ are dwarf forms
Indigofera kirilowi
Kirilow Indigo
Shrub 5 3' Sometimes killed to the ground by severe winters
Jasminum nudiflorum
Winter Jasmine
Shrub 6 3' Stems remain green in winter; 3’ spacing
Juniperus chinesis
‘Compact Pfitzer’
‘San Jose’
Shrub 5 2' Slow growth rate;
2’ spread; 18" spacing
6’ spread; 5’ spacing- All Junipers subject to Red Spider Mites; like dry soil, circumneutral
Juniperus chinensis sargenti
Sargent Chinese Juniper
Shrub 5 1' Spreads 8’ to 10’; 3’ - 5’ spacing - All Junipers subject to Red Spider Mites; like dry soil, circumneutral
Juniperus communis saxatilis
Mountain Common Juniper
Shrub 3 1' 6’ spread; 3’ - 5’ spacing - All Junipers subject to Red Spider Mites; like dry soil, circumneutral
Juniperus conferta
Shore Juniper
Shrub 6 1' Sandy soil - All Junipers subject to Red Spider Mites; like dry soil, circumneutral
Juniperus horizontalis (Var.)
Creeping Juniper
Shrub 3 12" - 18" All Junipers subject to Red Spider Mites; like dry soil, circumneutral
Juniperus procumbens
Japanese Garden Juniper
Shrub 6 2' Steel blue-green in winter; Spread 4’- 5’; spacing 3’ - All Junipers subject to Red Spider Mites; like dry soil, circumneutral
Juniperus sabina ‘Tamarix’
Tamarix Savin Juniper
Shrub 5 2' Withstands limestone soil; 15’ spread - All Junipers subject to Red Spider Mites; like dry soil, circumneutral
Juniperus scopulorum
‘Silver King’
Shrub 6 2' Silvery blue foliage; spread 8’ - All Junipers subject to Red Spider Mites; like dry soil, circumneutral
Juniperus virginiana
‘Silver Spreader’
Shrub 3 2' Silvery grey foliage; 8’ spread; cedar-apple rust - All Junipers subject to Red Spider Mites; like dry soil, circumneutral
Leucothoe catesbaei
Drooping Leucothoe
Shrub 5 3' Evergreen; sun; acid soil; can be maintained at 18"; spacing 3’
Liriope spicata
Creeping Liriope
(Lilyturf)
Herb 5 8" - 12" Grasslike foliage; shade or sun; semi-evergreen; 12" spacing
Lonicera henryi
Henry Honeysuckle
Vine 5   More hardy than Halls Honey-suckle; evergreen; shade or sun
Lonicera japonica halliana
Halls Japanese Honeysuckle
Vine 5   Will escape and become a pest; grows 18’ to 20’ a year; semi-evergreen; sun or shade; 3’ spacing
Lycium halimifolium
Matrimonyvine
Vine-shrub 5 9' Poor soil; sun
Mahonia repens
Creeping Mahonia
(Dwarf Holly-grape)
Shrub 6 10" Sun or shade; good flower display; dry soil; evergreen; 12" spacing
Mentha (spp.)
Mints
Herb 4 1' - 2' Aromatic, moist soils can become a pest
Mitchella repens
Partridgeberry
Vine 4 2" Shade; moist, acid soil; transplant in sod; terrarium
Pachistima canbyi
Canby Pachistima
Shrub 6 12" Acid, moist, well drained soil; evergreen; shade or sun; 12"-18" spacing
Pachysandra terminalis
Japanese Pachysandra
Vine 6 6" Evergreen; shade; 6" - 12" spacing
Parthenocissus quinquefolia
Virginia Creeper
Vine 4   Can become a pest; 6 - 10 feet a year; poor soil; shade or sun
Phalaris arundinacea picta
Ribbongrass
Herb 4   Variegated; moist soil; sun or shade
Phlox subulata
Moss Phlox
(Ground-Pink)
Herb 3 2' - 4' Dry soil; sun
Polygonum auberti
SiIvervine Fleeceflower
Herb 3   Very weedy; 10’-15’ per year; dry soil; sun
Polygonum cuspidatum
compactum
Japanese Fleeceflower
Herb 5 2" Very weedy; dry soil; sun; 24" - 36" spacing
Pueraria thunbergiana
Thunberg Kudzubean
(Kudzu Vine)
Herb-vine 6   Good for roadsides; 60’ year; can become a pest
Rhus aromatica
Fragrant Sumac
Shrub 4 3' Poor soil; sun
Robinia hispida
Roseacacia Locust
Shrub 6 3' Dry banks; sun
Rosa ‘Max Graf’ Shrub-Vine 3 3' - 4' Best viewed at a distance; sun; hybrid rugosa
Rosa rugosa repens
Trailing Rugosa Rose
Shrub 3   Sun
Rose wichuraiana
Wichura Rose
Shrub-Vine 6 1' Semi-evergreen; especially good on banks; sun
Rubus Iaciniatus
Cutleaf Blackberry
Shrub-Vine 6 2' Very thorny; good barrier
SaIix tristis
Dwarf Pussy Willow
Shrub 3 1' Moist, Sterile soil; sun
Santolina chamaecyparissus
Cypress Lavendercotton
Herb 7 1 '- 2' Limited use; aromatic; spacing 24"
Sedum acre
Goldmoss Stonecrop
Herb 4 3" Evergreen in warm climates; dry soil; shade or sun
Symphoricarpos orbiculatus
Indiancurrant Coralberry
Shrub 3 3' Variety ‘Hancock’ very good; dry soil; sun
Thymus serpyllum
Mother-of-thyme
(Creeping Thyme)
Herb 5 1" Good between stepping stones; 6"-12" spacing; many cultivars; Aromatic
Thymus vulgaris
Common Thyme
Herb 6 3" - 8" Aromatic
Vaccinium angustifolium Iaevifolium
Smoothleaf Lowbush Blueberry
Shrub 3 8" Rockery; poor soil; shade or sun
Veronica (spp.)
SpeedwelI
Herb 4 2" - 12" Can become a pest
Vinca minor
Common Periwinkle
(Myrtle)
Vine 5 9" Combine with bulbs and shrubs for good effect; shade or sun; evergreen; 9"spacing
Waldsteinia fragarioides
Barrenstrawberry
Herb 5 4" Grows into a mat; fruit inedible; dry soil. evergreen; shade or sun
Xanthorhiza simplicissima
Yellowroot
Shrub 5 2' Moist soil; grows to a uniform height; shade or sun; 2’ spacing
Yucca filamentosa
Adamsneedle Yucca
Shrub 5 2' Roadsides; poor soil; ever-green
**Zone 3 = -40F to -30F
Zone 4 = -30F to -20F
Zone 5 = -20F to -l0F
Zone 6 = -10F to 0F