Can Ground Covers Spread In Rock Gardens

Groundcover Surrounding Stepping Stones In Garden

While true to their name, groundcovers (or ground covers) do a lot more than simply cover bare soil. Part of a vast universe of versatile and problem-solving plants, they range from feathery grasses that never need mowing to soggy-soil-loving ferns to full-sun perennials that blanket hard-to-tend hills with fragrant blooms. Some groundcovers even withstand foot traffic, making them ideal as filler between stepping stones or as a substitute for a lawn.

Characterized, in part, by how wide-ranging they are, groundcovers can be evergreen or deciduous, low- or tall-growing, clump-forming, trailing, or weeping. But they also share common traits.

All groundcovers spread, colonizing areas often relegated to mulch or where turfgrass fears to take hold. And when chosen wisely to match a specific site, almost all of them reduce the need for water, fertilizer, and other routine maintenance. Best of all, they help prevent weeds by shading the soil and growing so densely that unwanted seeds can't find their footing.

Read on to learn more about the different types, how to choose groundcover, and get tips on plant and care for them. With our help, you're sure to find the perfect plants to thrive and beautify your property.

Shown: To ensure success in your yard, pick varieties that fill in fast enough to choke out weeds yet aren't invasive. And match them to your existing soil, sun, and moisture conditions. Here, a carpet-like groundcover fills in between stepping stones along a path bordered by chartreuse sedum and purple-flowering catmint.

Groundcovers: Important Questions to Ask

Man Adding Small Plants To Yard With No Grass

What do they cost?

As little as $1 to $4 per plant in bare root bundles or by the flat from a nursery or a garden center. Expect to pay $5 to $9 for plants in 4-inch pots and $10 or more for plants in gallon-size containers.

DIY or hire a pro?

Even folks who are new to gardening can handle most groundcover projects, but if replacing an entire lawn or blanketing an expansive hillside, you might want help from a landscaper.

What is maintenance like?

Water and weed until the plants fill in. After that, many groundcovers can be virtually maintenance-free.

How tall do they get?

The majority are 2 to 18 inches, but they can easily top 2 or even 3 feet. There are also tiny ground-huggers that max out at just 1 inch tall.

Benefits of Groundcovers

They save time and money.

Compared with a lawn, there's no mowing, little weeding, and minimal, if any, watering or fertilizing once the plants are established. And unlike with many fussier plants, there's little need for deadheading, cutting back spent growth, dividing, or replanting.

They're great mimics.

When planted in large swaths, groundcovers can give you the openness of a grassy lawn but with more texture. Small drifts of three or more plant types can give the layered look of flower beds but without the boom-and-bust cycles of annuals and perennials.

They ease transitions.

Groundcovers create attractive buffer zones between lawns and natural woodland areas. They also soften the look of paved surfaces when used along pathways, patios, driveways, and retaining walls.

They control erosion.

Massed plantings tend to slow the movement of rainwater down a slope while the foliage cushions the punch and the roots help bind the soil and absorb moisture. Plus, you don't have to worry about slipping as you tend the plants since there's barely any actual work to do.

Shown: Flagstones surrounded by a blanket of thyme serve as an informal walkway.

Where to Use Groundcovers

Lawns

To mimic the green-carpet effect, a groundcover should stay relatively short and spread into a fairly uniform blanket. Stick with a single species for the most realistic effect. The plants must also withstand foot traffic—unless your pseudo-lawn is just for looks, such as the one shown here. Blanketed with low-growing juniper, it has a tidy appearance year-round with no upkeep.

Gardens

Arranged in small drifts or clumps, groundcovers alone can fill a bed with interesting foliage and flowers. Go for less-aggressive species that spread at similar speeds so that they won't compete. Here, a well-behaved mix of purple-leaved ajuga, fine-textured thyme, and mounding Japanese forest grass hugs a bluestone walk.

Hillsides

Drought-tolerant plants tend to do best since hillsides are often windy and sunny and difficult to irrigate. To prevent erosion, choose plants that root tenaciously and cover the ground year-round. 'Bee's Bliss' salvia (S. sonomensis), shown here, has the bonus of showy purple flowers.

Paths and Patios

To fill spaces between pavers and stepping stones, choose plants that stay short and thrive in gravel or sandy soil. The flagstone path shown here has a lush look, thanks to baby's tears (Soleirolia soleirolii). Scented plants, such as thyme, are great too, but if people will be barefoot, avoid flowering types—they can attract bees.

Around Trees

Look for shade-tolerant varieties that don't need regular cutting to look tidy, since a string trimmer can damage tree trunks. Unlike turf, the ring of hardy geraniums shown here happily grows in partial shade and requires little tending. When planting under conifers, keep in mind that their branches shed water. Plants that like dry shade will grow best.

Types of Groundcovers

Carpet-Forming

'Snow In Summer' (Cerastium Tomentosum) Groundcover

Plants that completely blanket areas are the most economical and are great for erosion control. But some can invade a nearby lawn or perennial beds unless stopped by a switch in conditions—shade to sun, for example—or a physical barrier.

Shown: 'Snow in summer' (Cerastium tomentosum)

Clump-Forming

'Sweet Woodruff' (Gallium Odoratum) Groundcover

All groundcovers spread, but these more upright, slow movers tend to stay under control. They work well in small areas or where you want a defined edge, and for combining with other groundcovers, since each plant stays distinct.

Shown: 'Sweet woodruff' (Gallium odoratum)

Evergreen

Evergreens look good all year but often lack showy flowers. They are best for shading out weed seeds and hiding any debris that might blow in, a trait that's especially useful where groundcovers edge a walkway or a driveway.

Shown: (Delosperma cooperi)

Deciduous

Deciduous groundcovers die back or turn brown when temperatures drop below freezing. But the majority of the year, they offer color and texture, including spring flowers, summer berries, or bright fall foliage.

Shown: 'Lily-of-the-Valley' (Convallaria majalis)

Low-Growing

Plants that are under 12 inches tall are good for tight spaces and as edging but can require some weeding to look their best. Ground-huggers in the 1- to 3-inch range that tolerate foot traffic can be used between stepping stones.

Shown: 'Spotted deadnettle' (Lamium maculatum)

Tall-Growing

Plants that top 1 foot or more are best at shading out weeds and are often used for larger expanses and slopes. Be sure to select varieties with the mature height and spread you want. That way, you won't have to constantly cut them back.

Shown: 'Double bird's foot trefoil' (Lotus corniculatus 'Plenus')

How to Pick Your Plant

If you're wondering how they'll fill in, check the plant labels for the terms vigorous, moderate, or slow-growing, and choose accordingly. To see which zone fits your region, check the USDA Plant Hardiness Zone Map at planthardiness.ars.usda.gov.

Sun Soaking Groundcovers

Plants that prosper with 4 or more hours of direct sunlight daily.

'Rozanne' hardy geranium (Geranium)

Zones 5–8, $16; springhillnursery.com

'Angelina' Stonecrop (Sedum rupestre)

'Angelina' Stonecrop (Sedum Rupestre) Groundcover

Zones 6–9, $9.95; greatgardenplants.com

'Big Ears' Lambs' Ears (Stachys byzantina)

'Big Ears' Lambs' Ears (Stachys Byzantina) Groundcover

Zones 4–9, $12; whiteflowerfarm.com

Shade-Loving Groundcovers

Bunchberry (Cornus Canadensis) Shade-Loving Groundcover

Plants that are successful with less than 4 hours of direct sunlight daily

Bunchberry (Cornus canadensis)

Zones 2–7, $9.95; forestfarm.com

Wild Ginger (Asarum canadense)

Wild Ginger (Asarum Canadense) Groundcover

Zones 2–8, $8; arrowheadalpines.com

Yellow Archangel (Lamium galeobdolon)

Yellow Archangel (Lamium Galeobdolon) Groundcover

Zones 4–8, $12; whiteflowerfarm.com

Moisture-Seeking Groundcovers

Tufted Hair Grass (Deschampsia Caespitosa) Groundcover

Plants that flourish in damp soil and tolerate occasionally soggy sites

Tufted hair grass (Deschampsia caespitosa)

Zones 5–9, $7.95; anniesannuals.com

'Black Scallop' Ajuga (Ajuga reptans)

'Black Scallop' Ajuga (Ajuga Reptans) Groundcover

Zones 3–9, $8.95; bluestoneperennials.com

Golden Creeping Jenny (Lysimachia nummularia 'Aurea')

Golden Creeping Jenny (Lysimachia Nummularia 'Aurea') Groundcover

Zones 3–8, $6.75; diggingdog.com

Drought Tolerant Groundcovers

Gray Santolina (Santolina Chamaecyparissus) Groundcover

Plants that, once established, survive on rainfall alone

Gray santolina (Santolina chamaecyparissus)

Zones 6–9, $8.49; highcountrygardens.com

'Blue Star' Juniper (Juniperus squamata)

Zones 4–9, $35; brokenarrownursery.com

Sweet-Smelling Groundcovers

'Purple Beauty' Moss Phlox (Phlox subulata) Groundcover

Plants with flowers or leaves that release pleasant aromas when crushed

'Purple Beauty' moss phlox (Phlox subulata)

Zones 3–8, $6.99; santarosagardens.com

Lemon Thyme (Thymus citriodorus)

Lemon Thyme (Thymus Citriodorus) Groundcover

Zones 6–9, $8.95; stargazerperennials.com

Roman Chamomile (Chamaemelum nobile)

Roman Chamomile (Chamaemelum Nobile) Groundcover

Zones 6–9, $7.49; stargazerperennials.com

Foot-Friendly Groundcovers

Irish Moss (Sagina Subulata) Groundcover

If labeled light traffic, these plants can be walked on a few times a week. Heavy traffic means several times a day.

Irish moss (Sagina subulata)

Zones 4–7, $9.95; greatgardenplants.com

Corsican Sandwort (Arenaria balearica)

Zones 4–7, $6.99; littleprinceplants.com

Blue Star Creeper (Isotoma fluviatilis)

Blue Star Creeper (Isotoma Fluviatilis) Groundcover

Zones 5–9, $9.95; greatgardenplants.com

Slope Colonizing Groundcovers

Scotch Heather (Calluna Vulgaris) Groundcover

Plants that prevent erosion and don't need watering or much other care

Scotch heather (Calluna vulgaris)

Zones 5–7, $7.75; diggingdog.com

'Brigadoon' St. John's Wort (Hypericum calycinum)

'Brigadoon' St. John's Wort (Hypericum Calycinum) Groundcover

Zones 5–9, $9.95; bluestoneperennials.com

Bearberry (Arctostaphylos uva-ursi)

Bearberry (Arctostaphylos Uva-Ursi) Groundcover

Zones 2–6, $11; prairienursery.com

Wildlife Attracting Groundcovers

Wintergreen (Gaultheria Procumbens) Groundcover

Plants that provide food or shelter for birds, butterflies, and bees

Wintergreen (Gaultheria procumbens)

Zones 3–8, $2; burntridgenursery.com

Candytuft (Iberis sempervirens)

Candytuft (Iberis Sempervirens) Groundcover

Zones 5–9, $13; whiteflowerfarm.com

'Sugar Plum' Coral Bells (Heuchera)

'Sugar Plum' Coral Bells (Heuchera) Groundcover

Zones 3–8, $18; stargazerperennials.com

Invasive Groundcovers

Many groundcovers are listed as invasive species in some states because they spread through forests and wetlands, smothering native plants. Others aren't officially listed but still creep into nearby lawns or gardens.

Often, plants prove problematic only in certain climates. Pachysandra, for instance, runs rampant in parts of the East but behaves in the West. So before you buy, check your state's invasives list (invasivespeciesinfo.gov).

And avoid these five, which are widely considered to be troublemakers: English ivy (shown), cypress spurge (Euphorbia cyparissias), spearmint (Mentha spicata), common periwinkle (Vinca minor), and Japanese barberry (Berberis thunbergii).

Care and Planting Tips

More is better.

You'll get faster coverage by planting small plants and spacing them close together than from larger, mature plants that are widely spaced. Plus, if a few plants die, a dense planting means others are nearby to fill in.

Coddle the young.

Even the hardiest groundcovers need help in the beginning. If the weather is dry, water frequently—1 inch a week.

Patrol for weeds.

While your plants are still getting established, check them frequently and pull out any weeds. Use a dandelion weeder to get the whole root. Don't rely on weed cloth; it's not always effective.

Keep rodents away.

Where rats and mice are a problem, opt for deciduous, nonvining varieties. Many types of evergreen ivy, for instance, provide a thick blanket of year-round cover—ideal for nesting—and can even serve as a ladder into nearby trees.

Replacing a Lawn? Don't Dig—Smother

If converting turfgrass to groundcover, there's no need to rip it out or kill it with herbicide. Just mow as low as possible in fall, and cover the area with cardboard followed by a thick, 8-inch layer of mulch (free from many public-works departments). In spring, pull back areas of remaining mulch as needed to reveal soil ready for planting. The leftover blanket of mulch will help keep moisture in and weeds out.