Areas planted with ground covers provide an increasingly popular alternative planting an entire landscape with lawn grasses. They require far less maintenance (mowing, watering, fertilizing) than areas planted with lawn grasses, and are an important part of sustainable landscaping.
In addition, areas planted with ground covers establish an effect in the landscape that is impossible to create with lawns. They can add beauty and interest to home landscapes by providing variations in height, texture and color that enrich their surroundings.
Ground covers can reduce maintenance, beautify problem areas and create a whole new dimension in your landscape.
WHAT THEY ARE AND HOW WE USE THEM
The term ground cover is applied to low growing plants, other than turf grass, used to cover areas of the landscape. Evergreen plants – including perennials, dwarf shrubs and vines – that have a sprawling, or spreading habit are most often used.
The plants used for ground covers generally grow less than one foot in height, but taller growing plants are also used appropriately in certain landscape situations on a larger scale.
In addition to the beauty they provide, ground covers also have practical uses.
CHOOSING A GROUND COVER
The first factor you need to consider when selecting a ground cover is the growing conditions where it will be planted – such as sunny or shady (see definition of light terms on page 11). This will determine the group of ground covers you can choose from.
From the possible choices suitable for the growing conditions, you then must carefully consider the characteristics you would like the ground cover to have – such as height, texture, color, etc.
You should also look at the size of the area to be planted. Some ground covers are only suitable for smaller areas for a variety of reasons, and some do not spread especially fast. These would not be the best choices for covering large areas.
Only the most reliable, fast spreading and reasonably priced ground covers should be considered for large areas. Monkey grass/mondo grass (Ophiopogon japonicus), creeping lily turf (Liriope spicata), liriope (Liriope muscari) and Japanese ardisia (Ardisia japonica), for instance, are good choices for shade to part shade. Asiatic jasmine (Trachelospermum asiaticum) and liriope (Liriope muscari) are excellent for sun to part shade.
PREPARING THE PLANTING AREA
Whatever type of ground cover you choose, proper preparation of the planting area will help ensure good establishment and faster growth.
If you are working under a tree you must try to minimize damage to the tree’s roots. If the tree’s roots are shallow and you can’t easily work the soil, it would be best to spread 4 to 6 inches of a light, high organic soil mix (such as blended topsoil or garden soil) over the area, and plant in that.
PLANTING
Planting ground covers from November to March takes advantage of the cool, moist weather that occurs then and helps with successful establishment. Fall planting is especially advantageous. But, ground covers growing in containers can be successfully planted year round. More careful attention will need to be paid to proper watering when planting is done during hot weather.
For best results, plant the ground cover plants at the proper spacing. This varies with the type of ground cover chosen, so check with the staff at the nursery. Evenly spaced plantings will fill in and provide an even coverage over the area.
Small ground cover plants are usually spaced 6 to 8 inches apart. This includes plants growing in 3- to 4-inch containers.
Wider spacing can be used for rapidly spreading ground covers and plants growing in quart, trade-gallon or full-gallon containers.
If small shrubs are being used as ground covers (this includes junipers, dwarf gardenia and dwarf azaleas), use a 2-foot spacing or more between plants.
Planting closer than optimum results in faster covering, but plants will probably become overgrown.
Although planting at the recommended spacing will provide quicker coverage, you may find the cost higher than you expected. Generally, budget what you can to the project, purchase as many plants of ground cover as your budget will allow, and evenly space them in the area to be planted. As more funds become available, purchase and plant additional ground cover plants evenly spaced among those already planted.
In the case of monkey grass and liriope, you will get faster coverage by dividing the clump in a pot in half and planting the divisions twice as close as the recommendation for planting the whole pot in one spot.
Be sure to plant ground covers at the same level they were growing in the container. Planting too deeply can create problems.
After the area is planted, apply an inch or two of mulch such as leaves (chopped is best), pine bark, fine wood chips or pine straw. Until the ground cover fills in (generally about one to three years after planting), weed control is very important. Your best defense is a good layer of mulch. Hand weed regularly as necessary to maintain good weed control. In addition, most ground covers spread faster when mulched.
Water the area thoroughly to settle in the new planting. To promote establishment and growth through the first year after planting, continue to water regularly whenever rainfall does not occur for a week – particularly during the heat of summer.
MAINTENANCE
WATERING
Watering is most important while the ground cover is establishing – for about a year after planting. Most well-established ground covers do not need regular irrigation, although you will need to use your judgment, especially during the warmer summer months. Especially drought tolerant ground covers include Asiatic jasmine, junipers, yarrow and liriope. Less drought tolerant ground covers include ligularia and ferns
Water is best applied with sprinklers or in ground irrigation systems as you would water your lawn.
FERTILIZING
Fertilize ground covers in March with a general purpose fertilizer following label directions. A fertilizer with a 3:1:2 or 4:1:2 ratio, such as 15-5-10 or 16-4-8 or anything similar, generally works well. Where faster growth is desired, as in ground cover plantings that have not yet filled in the area, a second fertilizer application may be made in June or July.
PRUNING
Pruning is done to control the growth of ground covers, groom for improved appearance or rejuvenate.
Vining ground covers, such as Asian jasmine and English ivy, will need to be trimmed along the edges of the bed occasionally to keep them neat. Asian jasmine will also need to be sheared back occasionally using a string trimmer to keep it at the desired height – generally about 4 to 6 inches.
Ground covers such as liriope, monkey grass and Japanese ardisia may be trimmed back to within a few inches of the ground in late February to remove accumulated brown foliage, rejuvenate by stimulating new growth and improve the appearance. This can be done with a string trimmer or mower set at a high setting.
Low growing shrubs used as ground covers may be pruned to shape and control as needed or to remove dead growth or branches. For flowering shrubs, pruning is best done right after they finish their major flowering period.
Aspidistra and ferns are generally pruned just to remove any dead or unattractive foliage. Aspidistra plantings may be cut back to the ground, but expect it to take 2 growing seasons for the planting to regain a full appearance.
WEED CONTROL
Hand weeding and mulching will often provide all of the weed control that is needed. However, herbicides may be useful in some situations.
Weed seeds that germinate and grow in the ground cover can be controlled by the application of a preemergence herbicide. These herbicides do not control existing growing weeds, but will keep weed seeds of various grasses and broadleaf weeds from germinating successfully and growing in the area. Look for products with active ingredients such as trifluralin, oryzalin, pendimethalin, prodiamine, trifluralin + benefin and isoxaben. Check with your local nurseries for the products they carry with these active ingredients. Read the label carefully before purchasing to make sure the product you intend to use is safe for the type of ground cover you have and will control the particular weeds that are causing problems.
Grassy weeds growing in ground covers can be controlled using a selective grass killer like sethoxydim or fluazifop. You may treat as needed following label directions carefully. Check with your local nurseries for the products they carry with these active ingredients. Read the label carefully before purchasing to make sure the product you intend to use is safe for the type of ground cover you have and will control the particular weeds (grasses) that are causing problems. If the ground cover you have does not appear on the label, there is a chance it might be damaged.
Imazaquin is labeled for use on some ground covers, and will help control sedges (nutsedge, nutgrass, cocograss, kylinga) and certain broad leaf weeds. Check with your local nurseries for the products they carry with this active ingredient. Read the label carefully before purchasing to make sure the product you intend to use is safe for the type of ground cover you have (including any shrubs or ornamental plants growing in the ground cover) and will control the particular weeds that are causing problems.
PEST PROBLEMS
Like all landscape plants, ground covers may be occasionally bothered by insect or disease problems. Mites and fungal diseases are fairly common on junipers. Ajuga and English ivy are prone to crown and root rots. But, overall, ground covers tend to have relatively few insect and disease problems.
To properly diagnose pest problems and get the right recommendations, contact your local Parish LSU AgCenter Extension office at the first sign of symptoms.
GROUND COVERS FOR SHADE TO PART SHADE:
Liriope (Liriope muscari) many different cultivars
Creeping lily turf (Liriope spicata)
Monkey grass, Mondo grass (Ophiopogon japonicus);
Dwarf monkey grass cultivars (Ophiopogon japonicus ‘Nana’ and others) suitable for small areas
Asian jasmine (Trachelospermum asiaticum)
Japanese ardisia (Ardisia japonica)
Cast iron plant (Aspidistra elatior, best used in total shade)
English ivy (Hedera helix)
Ligularia (Farfugium japonicum)
Algerian ivy (Hedera canariensis)
Periwinkle (Vinca major, an excellent variegated form is available)
Ajuga (Ajuga reptans, use in small areas as it is prone to crown rot)
Strawberry begonia (Saxifraga stolonifera; best used in shady, damp small areas)
Many ferns such as holly fern (Cyrtomium falcatum), wood fern (Thelypteris kunthii), sword fern (Nephrolepis cordifolia) and utumn fern (Dryopteris erythrosora) to name a few
GROUND COVERS FOR PART SUN TO FULL SUN:
Asian jasmine (Trachelospermum asiaticum)
Liriope (Liriope muscari) many different cultivars
Aztec Grass (Ophiopogon species)
Flax lily (Dianella tasmanica ‘Variegata’)
Lily of the Nile (Agapanthus)
Sedum (Sedum acre, S. album)
Dwarf bamboo (Bambusa sasa pygmaea)
Low growing junipers (Juniperus chinensis procumbens and J. horizontalis cultivars especially)
Dwarf gardenia (Gardenia jasminoides)
Dwarf lantanas (Lantana camara)
Trailing lantana (Lantana montevidensis)
Daylily (Hemerocallis)
Perennial verbenas
Yarrow (Achillea millefolium)
Best Ground Covers for Large Areas
Liriope (Liriope muscari) many different cultivars
Creeping lily turf (Liriope spicata)
Monkey grass, Mondo grass (Ophiopogon japonicus); dwarf monkey grass is suitable for small areas
Asian jasmine (Trachelospermum asiaticum)
Japanese ardisia (Ardisia japonica)
Cast iron plant (Aspidistra elatior, best used in total shade)
Flax lily (Dianella tasmanica ‘Variegata’)
Information for Ground Cover Chart
Columns will be Name, Height, Light and Comments
Ajuga ‘Caitlin’s Giant’
Ajuga repens
4 to 6 inches
Shade to Part shade
Low growing spreading perennial; purple foliage; spikes of cobalt blue flowers in spring; there are many cultivars of ajuga with variegated foliage of various colors and sizes; use only in small areas for detail work; prone to crown rot and root rot
Asian Jasmine
Trachelospermum asiaticum
4 to 6 inch deep mat
Full sun to Part shadeExcellent fast growing vine for covering large areas; shear back to 4 to 6 inches annually; edge sides of beds regularly; do not plant shrubs or other plants into areas with Asian jasmine
Aspidistra, Cast Iron Plant
Aspidistra elatior
2 feet
Shade to Full shade
Tall ground cover for deep shade; sword shaped dark green leaves
Autumn Fern
Dryopteris erythrosora
12 to 18 inches
Shade to Part Shade
Attractive evergreen fern; new growth has coppery red color; tough and reliable
Aztec Grass
Ophiopogon species
12 to 18 inches
Full sun to Part shade
Leaves highly variegated with white are narrow and grass-like
Creeping Juniper
Juniperus horizontalis, Juniperus procumbens
12 to 18 inches
Full sun
Excellent drought tolerant ground cover for sunny, dry areas with good air circulation; numerous cultivars
Creeping Lily Turf
Liriope spicata
8 to 10 inches
Shade to Part shade
Grass-like foliage; reliable for large areas, better than L. muscari as a ground cover since it spreads faster; ‘Silver Dragon’ is a variegated cultivar
Dwarf Bamboo
Arundinaria pygmaea
12 to 15 inches
Full sun to Part shade
Aggressive, fast spreading, tough plant for sunny areas; may be hard to contain in desired area; cut back foliage in late winter each year to rejuvenate
Dwarf Gardenia, Radicans Gardenia
Gardenia jasminoides ‘Radicans’
24 to 30 inches tall
Full sun to Part shade
A low growing shrub with a spreading growth habit; prefers acidic soil – pH 5.5; fragrant white flowers in early summer and sporadically in fall
Dwarf Lantana
Lantana camara
18 to 30 inches
Full sun to Part sun
May be killed by temperatures in the teens, but generally hardy; colorful flowers through the summer attractive to butterflies; shrubby spreading growth habit
English Ivy
Hedera helix
8 inch deep mat
Shade to Part sun
Useful for covering large areas and slopes; may be damaged by root rot; use vigorous, fast growing cultivars as ground covers
Algerian Ivy
Hedera canariensis
8 inches
Shade to Part Shade
Similar to English ivy but with larger leaves; a nice variegated cultivar is available
Holly Fern
Cyrtomium falcatum
12 to 20 inches
Shade to Part Sun
Bold, coarse evergreen foliage; almost shrub-like; tolerates dryer soil than most ferns
Japanese Ardisia
Ardisia japonica
8 to 10 inches
Shade to Part shade
Scattered bright red berries in winter; choose cultivars with plain green leaves for ground cover planting
Ligularia
Farfugium japonica
12 to 30 inches depending on cultivar
Part shade to Shade
Depending on the cultivar, of which there are many, the leaves may be 4 to 10 inches across, round to kidney-shaped, plain green, gold-spotted or splashed with white, and have smooth or richly ruffled edges. The plants have a mounded shape. Late summer flowers are yellow daisies.
Lily of the Nile, Agapanthus
Agapanthus species and hybrids
12 to 24 inches or more, depending on cultivar
Full sun to Part shade
Strap shaped clumps of medium green; tall stems hold round clusters of flowers in shades of blue or white above the foliage in May and June; tip burn of foliage is common in sunny areas during hot late summer conditions; foliage damaged by temperatures in the teens
Liriope, Lily Turf
Liriope muscari
8 to 18 inches depending on cultivar
Shade to Full sun
Grass-like foliage; reliable for large areas; several cultivars of varying heights, some with variegated foliage; spikes of purple or lavender flowers
Monkey Grass; Mondo Grass
Ophiopogon japonicus
8 to 10 inches
Part sun to Shade
Thin dark green leaves are grassy in appearance; one of the most reliable ground covers; excellent for larger areas;
Dwarf monkey grass cultivars
Ophiopogon japonicus ‘Nana’ and others
2 to 3 inches
This is a very, attractive neat ground cover that has a low, dense growth habit. But, it’s slow rate of spread and high cost make it suitable only for small areas; excellent for use between stepping stones and small detail areas in the landscape
Periwinkle
Vinca major
8 to 14 inches
Part shade to Part sun
A spreading vine with round, medium green leaves, it does not form a dense ground cover and is prone to invasion by weeds; blue flowers in late spring; a very nice variegated form is available and is also suitable for use as a ground cover
Sedum
Sedum mexicanum and Sedum album
2 to 3 inches
Full Sun to Part shade
There are many types of low growing, spreading sedums – these two species are generally considered most reliable; low growing, spreading plants suitable for small areas or detail work; small, star-shaped flowers in spring may be yellow (S. mexicanum) or white (S. album)
Strawberry Geranium
Saxifraga stolonifera
4 inches
Shade to Part shade
Small plant for detail work or small shady, moist areas; round dark green leaves with silver veins; stalks of small, white flowers in spring
Trailing Lantana
Lantana montevidensis
6 to 18 inches
Full sun to Part sun
Spreading plants with purple or white flowers in spring/early summer and late summer; may be killed by temperatures in the teens; use in small areas
Variegated Flax Lily
Dianella tasmanica ‘Variegata’
18 to 24 inches
Full sun to Part shade
Clumps of iris-like foliage dramatically variegated with white; damaged by temperatures in the teens – cut back damaged growth and it rapidly recovers; leaf spot disease sometimes a problem
Yarrow
Achillea millefolium
8 to 12 inches, taller when blooming
Full sun to Part sun
Low, fine textured, ferny foliage; tall stalks24 inches tall of flat, white flower clusters in spring or early summer; hybrids in many other colors; tolerant of dry conditions; use in small areas
Definition of light terms:
Full sun – 8hours or more of direct sun
Part sun – 4 to 6 hours of direct sun or afternoon sun
Part shade – about 4 hours of morning sun
Shade – about 2 hours of direct sun or dappled light
Full shade – little or no direct sun
Prepared by:
Dan Gill
Consumer Horticulture Specialist
LSU AgCenter