The promise is irresistible. Plant something that spreads, let it knit together, and weeds have nowhere to go. It is true, but not in the way the plant tags suggest.
What does the work is light at soil level. A closed cover lets through so little daylight that weed seed never germinates. One that has not closed is just plants with bare dirt between them, and bare dirt grows weeds. The difference sits in those first one to three years. Below are 20 species by site, with height, rate of spread, spacing and an honest verdict on how well each holds weeds down.
| Key figure | Guideline |
|---|---|
| Plants per square metre | 6–12 for most perennials |
| Most common spacing | 30–40 cm (12–16 in), staggered |
| Time to closed cover | 1–3 growing seasons |
| Weeding during establishment | Every 3–4 weeks, years 1–2 |
| Planting window | Late spring, or 6 weeks before frost |
| Mulch depth | 5–7 cm (2–3 in) |
| Cardboard under mulch | Plain corrugated, overlapped 15 cm (6 in) |
| Hardiness | All species hardy to USDA zone 6 or colder |
| Exposure | Full sun through deep dry shade |
| Soil pH | 6.0–7.0 for most, 4.5–5.5 for lingonberry |
| Watering year 1 | 20 litres per m² a week (0.5 in) in drought |
| Maintenance level | High in years 1–2, very low from year 3 |
Contents
- How do ground cover plants actually stop weeds?
- Preparing the site before you plant
- How many plants per square metre do you need?
- Ground covers for dry sun
- Ground covers for dry shade
- Ground covers for moist shade
- Ground covers for slopes and erosion
- Ground covers between pavers that take foot traffic
- Evergreen ground covers for winter interest
- Ground covers that flower for bees
- The full comparison chart
- Which ground covers turn invasive and which will you regret?
- How long before the cover closes?
- Care in the first years, step by step
- Zone and planting chart
- Common mistakes
- Frequently asked questions
How do ground cover plants actually stop weeds?
Three mechanisms work at once, and they are not equally strong in every species.
Shade matters most. Seed of chickweed, lamb's quarters, groundsel and annual bluegrass needs light to germinate, and a canopy passing less than five percent of daylight shuts that down. It is why a species with broad horizontal leaves, like bigroot geranium or bergenia, beats an airy clump of the same height.
Second comes competition for water and nutrients. A dense root mat in the top 10 cm (4 in) leaves a weed seedling nothing to grip. Fragrant sumac and creeping juniper work that way.
Third is physical cover through winter. An evergreen canopy blocks the germination flush of mild spells in late autumn and early spring, which is bigger than most gardeners realise. That is the advantage of lingonberry and bergenia over anything that dies back in October.
What ground cover cannot do
No ground cover removes established perennial root weeds. Goutweed, quackgrass, Canada thistle and bindweed store energy in their roots and push up through any mat. In the contest for water, goutweed wins. Weeds arriving from above, such as maple seedlings, get pulled by hand.
Preparing the site before you plant
This step decides whether the bed looks after itself or becomes a regret. Every guide says to clear the weeds first. Fewer say how, and almost none are blunt that one missed goutweed root takes the planting within three years.
Step one: identify the root weeds
Goutweed has leaflets in threes on a grooved stalk and white rhizomes that snap at the lightest spade cut. Quackgrass has narrow pale blades and sharp white running roots. Canada thistle has prickly leaves and a deep spreading taproot. All regrow from root fragments.
Step two: starve them out
The only reliable chemical-free method is to deny them leaves long enough. Cover the area with plain cardboard or an old tarp, then 10 cm (4 in) of wood chips, and leave it a full season. Overlap the cardboard 15 cm (6 in) at the seams or quackgrass finds the gap. If the weed sits in one corner, dig that patch out 30–40 cm (12–16 in) deep and sift the soil.
Step three: cardboard and mulch at planting
Once the site is clean, plant, then lay cardboard between the plants with a hole for each one and top it with 5–7 cm (2–3 in) of bark or shredded leaves. The cardboard breaks down in a season and kills the weed seed in the top layer while it does.
Skip landscape fabric. Your ground cover's runners cannot root through it, and those runners are what closes the cover. Within five years a layer of silt sits on the fabric with weeds rooting through the weave, far worse to clear than bare soil ever was.
How many plants per square metre do you need?
This is the question almost nobody answers with numbers, and it decides both the cost and how long you will be weeding. Plants per square metre equal one divided by the spacing in metres squared. A staggered grid uses about 15 percent more plants and closes more evenly.
| Spacing | Plants per m² | Plants per 10 m² | Plants per 100 sq ft | Suits |
|---|---|---|---|---|
| 20 cm (8 in) | 25 | 250 | 230 | Paver joints |
| 25 cm (10 in) | 16 | 160 | 150 | Thyme, Irish moss |
| 30 cm (12 in) | 11 | 110 | 100 | Wild ginger, stonecrop |
| 35 cm (14 in) | 8 | 80 | 75 | Geranium, sedge, foamflower |
| 40 cm (16 in) | 6 | 60 | 60 | Bergenia, barrenwort |
| 50 cm (20 in) | 4 | 40 | 37 | Bearberry, catmint |
| 60 cm (24 in) | 3 | 30 | 26 | Sweetfern |
| 80 cm (32 in) | 1.5 | 16 | 15 | Creeping juniper |
| 100 cm (39 in) | 1 | 10 | 9 | Fragrant sumac |
A worked example: 10 m² (108 sq ft) of bigroot geranium at 35 cm needs 80 plants. Drop to 50 cm and you need 40, but the cover closes one to two years later. Count that weeding before you save on plants. A common compromise is tight at the edges, looser in the middle. For more ideas by exposure, see the guides to shade perennials and perennials for full sun.
Ground covers for dry sun
South-facing, lean soil, maybe a gravel bed or the strip along a driveway. Water is the limit, and the upside is that most weeds struggle too.
Bearberry (Arctostaphylos uva-ursi)
Height 10–15 cm (4–6 in). Spread 20–30 cm a year. Spacing 50 cm (20 in), 4 plants per m². Site full sun, sandy acid soil, sharp drainage. Zones 2–6.
A native evergreen with small glossy leaves, pink bells and red berries. Weed suppression: very good once closed, which takes three to four years. It hates rich soil and root disturbance; mulch with pine needles.
Two-row stonecrop (Phedimus spurius, formerly Sedum spurium)
Height 10–15 cm (4–6 in). Spread 15–25 cm a year. Spacing 30 cm (12 in), 9–12 plants per m². Site full sun, lean well-drained soil. Zones 3–8.
A thick mat of fleshy leaves that goes weeks without water. 'Dragon's Blood' has wine-red foliage, 'John Creech' is the toughest. Weed suppression: good on lean soil, worse on rich soil, where the mat opens and grass seeds into it. Never rake it.
Moss phlox (Phlox subulata)
Height 10–15 cm (4–6 in). Spread 10–15 cm a year. Spacing 30–35 cm (12–14 in), 9 plants per m². Site full sun, dry to average soil. Zones 3–8.
A needle-leaved native that disappears under pink, white or lavender flowers in May. Weed suppression: good while dense, but old plants die out in the centre. Shear back by half after flowering and divide every four to five years.
Ground covers for dry shade
Under an old spruce, against a north wall, in the root zone of a maple. The hardest site in any garden: low light, no rain reaching the ground, tree roots taking the water first. Most perennials fade out within two years. These four do not.
Bigroot geranium (Geranium macrorrhizum)
Height 25–35 cm (10–14 in). Spread 20–30 cm a year. Spacing 35–40 cm (14–16 in), 6–8 plants per m². Site sun to deep dry shade, almost any soil. Zones 3–8.
The most reliable ground cover for cold gardens, and the best there is at dry plus dark. Aromatic semi-evergreen leaves and fleshy surface rhizomes that split easily. 'Bevan's Variety' is magenta, 'Ingwersen's Variety' soft pink. Weed suppression: excellent.
Pennsylvania sedge (Carex pensylvanica)
Height 20–25 cm (8–10 in). Spread 15–20 cm a year. Spacing 30–35 cm (12–14 in), 9 plants per m². Site dry shade to part sun, any soil that drains. Zones 3–8.
A native woodland sedge that runs gently on rhizomes and forms a fine soft turf under trees. Weed suppression: very good, and one of the few covers that takes root competition from beech and maple. Mow once in early spring at the highest setting.
Wild ginger (Asarum canadense)
Height 15–20 cm (6–8 in). Spread 10–15 cm a year. Spacing 30 cm (12 in), 9–12 plants per m². Site shade, humus-rich soil that is dry to average. Zones 3–7.
Large heart-shaped leaves on short rhizomes, with brown flowers hidden at ground level. Weed suppression: very good once closed, but it needs three years. The leaves shade the soil completely, so a closed stand is close to weed-proof.
Barrenwort (Epimedium × perralchicum 'Frohnleiten')
Height 30–40 cm (12–16 in). Spread 8–12 cm a year. Spacing 30–35 cm (12–14 in), 9 plants per m². Site dry shade under trees and shrubs. Zones 5–8.
Leathery leaves on wiry stems, bronze when new, with yellow flowers in April. Weed suppression: good, but only from year three. The slowness is the price of surviving dry shade at all. Shear last year's leaves in March or the flowers stay hidden.
Ground covers for moist shade
A north side with even moisture, a pond edge, the low ground under a birch. More choice here, and more weed pressure: moisture and humus favour everything.
Foamflower (Tiarella cordifolia)
Height 20–25 cm (8–10 in), flower stems 30 cm (12 in). Spread 15–25 cm a year. Spacing 35 cm (14 in), 7–9 plants per m². Site moist shade, rich slightly acid soil. Zones 3–8.
A native woodlander with maple-shaped leaves marked dark along the veins and airy white spikes in May. Weed suppression: good. It runs on short surface stolons and closes in two to three years. It will not take drought or heavy clay.
Bunchberry (Cornus canadensis)
Height 10–20 cm (4–8 in). Spread 15–20 cm a year. Spacing 30 cm (12 in), 9–12 plants per m². Site cool moist shade, acid humus-rich soil. Zones 2–6.
A dwarf native dogwood with whorled leaves, white bracts in June and scarlet berries. Weed suppression: good once established, which is the catch. It sulks in warm or limy soil and wants cool acid ground with a duff layer. Unbeatable where it is happy, a failure where it is not.
Sweet woodruff (Galium odoratum)
Height 15–20 cm (6–8 in). Spread 30–40 cm a year. Spacing 30 cm (12 in), 9 plants per m². Site shade, average to moist humus-rich soil. Zones 4–8.
Whorled leaves in neat tiers and white star flowers in May, with a hay scent as the foliage dries. Weed suppression: excellent, and one of the few covers that outcompetes weed seedlings on its own. The price is that it does not stay put. Give it a bounded area.
Ground covers for slopes and erosion
A bank steeper than 1:3 cannot be mown safely and washes out in every downpour. You need species that bind soil at several depths and root where branches touch down. Pin jute or coir netting the first year, or the mulch ends up at the bottom.
Creeping juniper (Juniperus horizontalis)
Height 15–20 cm (6–8 in). Spread 20–30 cm a year. Spacing 80–100 cm (32–39 in), 1–2 plants per m². Site full sun, dry sharply drained soil. Zones 3–9.
'Blue Rug' is flat and steel blue, 'Blue Chip' slightly taller. Evergreen and drought proof once rooted in. Weed suppression: good, but only after four to five years because the plants go in wide apart. Expect real hand weeding in between. It tolerates no wet soil.
Fragrant sumac (Rhus aromatica 'Gro-Low')
Height 60–75 cm (24–30 in). Spread 30–40 cm a year. Spacing 100 cm (39 in), 1 plant per m². Site full sun to part shade, any soil that drains. Zones 3–9.
A native suckering shrub with glossy three-part leaves, yellow spring flowers and scarlet autumn colour. Weed suppression: excellent. The layered branches and leaf litter stop almost everything, which is why it is standard on highway banks. Cut a third of the oldest stems down every third year.
Sweetfern (Comptonia peregrina)
Height 60–90 cm (24–36 in). Spread 25–35 cm a year. Spacing 60–80 cm (24–32 in), 2–3 plants per m². Site full sun, dry sandy acid soil. Zones 2–6.
A native suckering shrub with fern-like aromatic leaves that fixes its own nitrogen, which is why it colonises raw sandy banks nothing else holds. Weed suppression: very good in three to four years. Buy container-grown stock; bare-root transplants badly.
Ground covers between pavers that take foot traffic
The joint between stepping stones is a weed magnet: warm, bright and full of seed. A low cover there looks better than joint sand and shuts most of it out. The demands are steep: drought, heat and treading.
Creeping thyme (Thymus serpyllum)
Height 3–8 cm (1–3 in). Spread 10–15 cm a year. Spacing 25 cm (10 in), 12–16 plants per m². Site full sun, sandy lean soil. Zones 4–8.
The lowest of the genuinely tough covers and one of very few that takes treading. Pink or purple flowers in July are alive with bees. Weed suppression: moderate. The mat is dense but only centimetres deep, so dandelion and thistle push through.
Irish moss (Sagina subulata)
Height 2–5 cm (1–2 in). Spread 8–12 cm a year. Spacing 20–25 cm (8–10 in), 16–20 plants per m². Site sun to part shade, evenly moist but drained soil. Zones 4–8.
It looks like moss and is not, with tiny white flowers in June. Weed suppression: moderate. The cushion is tight but so low that taller weeds get through, and it browns out in a dry summer. Cut out the patch and press in healthy mat. Light traffic only.
Dutch white clover (Trifolium repens)
Height 10–15 cm (4–6 in). Spread 30–50 cm a year. Spacing sow 2–4 g per m² (1 lb per 1,000 sq ft), or 9 plants per m². Site sun to part shade, any soil. Zones 3–10.
Underrated. It takes daily traffic, fixes its own nitrogen and stays green in drought when turf goes brown. 'Microclover' is finer and lower. Weed suppression: good in a closed sward, moderate alone on bare soil. The flowers are among the best bumblebee forage anywhere, which means it hums where you walk barefoot.
Evergreen ground covers for winter interest
From November to April the foliage does the work, visually and against weeds, blocking the germination flush of mild spells in autumn and early spring.
Lingonberry (Vaccinium vitis-idaea)
Height 15–25 cm (6–10 in). Spread 10–15 cm a year. Spacing 30 cm (12 in), 9–12 plants per m². Site sun to part shade, acid well-drained soil at pH 4.5–5.5. Zones 2–6.
Hardy past the tree line, evergreen, and it gives you fruit. 'Koralle' is the most widely grown, 'Red Pearl' flowers twice. Weed suppression: moderate to good. The mat thickens only after three or four years, and only in acid soil.
Bergenia (Bergenia cordifolia)
Height 30–40 cm (12–16 in). Spread 8–12 cm a year. Spacing 40–45 cm (16–18 in), 5–6 plants per m². Site sun to shade, any soil that is not waterlogged. Zones 3–8.
Big leathery leaves that persist all winter and often flush wine red, with pink flowers in April, early enough to feed the first queen bumblebees. Weed suppression: good, but the clumps spread slowly, so plant close.
Ground covers that flower for bees
A ground cover need not be plain green. Choose nectar-rich species and the ground that excludes weeds also feeds bumblebees and solitary bees. More options are in the guide to bee friendly plants, and among drought-tolerant neighbours growing lavender is the obvious companion.
Catmint (Nepeta × faassenii)
Height 45–60 cm (18–24 in). Spread 10–15 cm a year as a clump. Spacing 45–50 cm (18–20 in), 4–5 plants per m². Site full sun, dry well-drained soil. Zones 3–8.
'Walker's Low' and 'Six Hills Giant' hold themselves up best. Violet-blue from late May, reblooming after shearing. Weed suppression: good once the plants meet, but they form clumps rather than runners, so years one and two mean weeding the gaps. Plant tighter than the tag says.
Large self-heal (Prunella grandiflora)
Height 15–25 cm (6–10 in). Spread 15–20 cm a year. Spacing 35 cm (14 in), 7–9 plants per m². Site sun to part shade, average soil. Zones 4–8.
Violet-blue flower spikes from June to August over a low mat of dark leaves, and one of the most visited perennials for long-tongued bumblebees. Weed suppression: good. It creeps on stolons and closes in two seasons.
The full comparison chart
All 20 species in one chart. The right-hand column is the verdict on how well each holds weeds down once it has closed. None does the job before then.
| Plant | Site | Height | Plants per m² | Rate of spread | Weed suppression | Zones |
|---|---|---|---|---|---|---|
| Bearberry | Dry sun | 10–15 cm | 4 | 20–30 cm/yr | Very good, yr 3–4 | 2–6 |
| Two-row stonecrop | Dry sun | 10–15 cm | 9–12 | 15–25 cm/yr | Good, lean soil | 3–8 |
| Moss phlox | Dry sun | 10–15 cm | 9 | 10–15 cm/yr | Good while dense | 3–8 |
| Bigroot geranium | Sun, dry shade | 25–35 cm | 6–8 | 20–30 cm/yr | Excellent | 3–8 |
| Pennsylvania sedge | Dry shade | 20–25 cm | 9 | 15–20 cm/yr | Very good | 3–8 |
| Wild ginger | Dry shade | 15–20 cm | 9–12 | 10–15 cm/yr | Very good, yr 3 | 3–7 |
| Barrenwort | Dry shade | 30–40 cm | 9 | 8–12 cm/yr | Good, yr 3–4 | 5–8 |
| Foamflower | Moist shade | 20–25 cm | 7–9 | 15–25 cm/yr | Good | 3–8 |
| Bunchberry | Moist acid shade | 10–20 cm | 9–12 | 15–20 cm/yr | Good if suited | 2–6 |
| Sweet woodruff | Moist shade | 15–20 cm | 9 | 30–40 cm/yr | Excellent | 4–8 |
| Creeping juniper | Slope, sun | 15–20 cm | 1–2 | 20–30 cm/yr | Good, yr 4–5 | 3–9 |
| Fragrant sumac | Slope, sun/part | 60–75 cm | 1 | 30–40 cm/yr | Excellent | 3–9 |
| Sweetfern | Dry sandy slope | 60–90 cm | 2–3 | 25–35 cm/yr | Very good, yr 3–4 | 2–6 |
| Creeping thyme | Pavers, sun | 3–8 cm | 12–16 | 10–15 cm/yr | Moderate | 4–8 |
| Irish moss | Pavers, part sun | 2–5 cm | 16–20 | 8–12 cm/yr | Moderate | 4–8 |
| Dutch white clover | Pavers, lawn | 10–15 cm | 9 or sown | 30–50 cm/yr | Good when closed | 3–10 |
| Lingonberry | Part sun, acid | 15–25 cm | 9–12 | 10–15 cm/yr | Moderate to good | 2–6 |
| Bergenia | Sun to shade | 30–40 cm | 5–6 | 8–12 cm/yr | Good | 3–8 |
| Catmint | Dry sun | 45–60 cm | 4–5 | 10–15 cm/yr | Good when closed | 3–8 |
| Large self-heal | Sun/part shade | 15–25 cm | 7–9 | 15–20 cm/yr | Good | 4–8 |
Which ground covers turn invasive and which will you regret?
The trait that makes a good ground cover, the ability to spread and crowd everything else out, makes it a problem in the wrong place. These are the ones most often regretted in cold-climate gardens.
Goutweed or bishop's weed (Aegopodium podagraria) – never plant it
It was sold for decades as the answer to dry shade, and the variegated form still is in places. It runs on brittle white rhizomes, regrows from every fragment and cannot be dug out of an established bed without lifting everything. The variegated form reverts to plain green and gets more vigorous. It is listed as invasive across the northern United States and Canada.
Periwinkle (Vinca minor) near natural areas
In a bounded bed against a foundation, periwinkle is a decent evergreen cover. Let it into a woodlot or meadow edge and it forms mats that stop all regeneration of native spring ephemerals. Ten years of cover is a serious job to clear. Keep a hard edge of stone, steel or mown turf around it.
Bugleweed (Ajuga reptans) running into the lawn
Bugleweed is handsome, flowers blue and takes shade. It also runs on stolons that root every few centimetres, and turf is no barrier. Three years on you have blue patches through the lawn, and the only cure is lifting every rosette by hand.
Creeping jenny (Lysimachia nummularia)
The golden form looks tame in a pot. In moist ground it takes over, roots at every node and cannot be weeded out of a lawn or pond margin. It is listed as invasive in wetlands across the Great Lakes and the Northeast. Foamflower gives the same effect with a boundary you can hold.
English ivy (Hedera helix) in North America
Hardy enough in zones 5 and 6, and that is the problem. In North America it smothers forest floors, climbs and kills mature trees, and birds spread the berries far beyond the garden. It is a listed noxious weed in Oregon and regulated in other states. In Britain it is a native with real wildlife value; in North America choose Pennsylvania sedge instead.
Others to watch
Yellow archangel (Lamiastrum galeobdolon) escapes into woodland from shade plantings. Wintercreeper (Euonymus fortunei) climbs and seeds into forest edges. Crown vetch (Securigera varia) is a listed invasive in many states. Treat anything spreading over 50 cm (20 in) a year as needing a physical edge.
How long before the cover closes?
One to three years at the right spacing, longer if you planted thin to save money. All that time you weed actively, and that is the part missing from almost every article.
Year one: full weeding
The bare soil between plants is a perfect seedbed. Go over the area every three to four weeks from May to September and pull anything that is not your ground cover while it is small. A weed at 10 cm already has roots competing with its neighbour.
Year two: targeted weeding
The fast species have closed and the slow ones still have gaps. Weed the gaps and edges every two months. Edges are always the weak point, because weeds walk in from outside.
Year three onward: patrol
Two passes a season is enough, one in May and one in August. You pick tree seedlings, dandelions and the odd grass. On 10 m² that is fifteen minutes a pass. The payoff is real, and it arrives in year three.
Fastest and slowest
Fastest to close: sweet woodruff, bigroot geranium, white clover and fragrant sumac, often by the second season. Slowest: barrenwort, bearberry, creeping juniper and lingonberry, at three to five years. If you will not keep weeding, choose from the first group.
Care in the first years, step by step
The sequence below works for every species here. What changes is the spacing in step five, taken from the chart above.
- Clear every perennial root weed the season before planting, with cardboard and chips or by digging out and sifting.
- Loosen to a spade's depth and work 5 cm (2 in) of compost into the top 15 cm, except where stonecrop, thyme or bearberry go.
- Soak the plants in their pots until the bubbles stop before setting them out.
- Mark the spacing with a tape. Uneven gaps are where weeds get in.
- Plant on a staggered grid, with the top of the root ball level with the soil surface.
- Water in at once with 5 litres (1.3 gal) per plant so the soil closes around the roots.
- Lay cardboard between the plants with a hole for each one, and cover with 5–7 cm (2–3 in) of bark or shredded leaves.
- Water 20 litres per m² a week in dry spells the first season, only in prolonged drought the second.
- Weed every three to four weeks through the first season. Pull with the root rather than snapping the top off.
- Top up the mulch in August of year one and May of year two wherever the layer has thinned.
- Shear species that go bare in the centre, such as moss phlox and catmint, after flowering.
- Divide and move plants from thick patches into the gaps in years two and three. Free material, best done in spring.
To build the border around your ground cover, start with the guide to perennials, and for colour that carries the season see long flowering perennials.
Zone and planting chart
Planting date decides how much root the plant makes before winter. In the coldest zones spring beats autumn: frost heave lifts an autumn-planted cover out before it anchors.
| USDA zone | Best spring planting | Last safe fall planting | Years to closed cover | Winter notes |
|---|---|---|---|---|
| Zone 3 | Late May to mid June | 10 August | 3–4 | Spring only; mulch against frost heave |
| Zone 4 | Mid May to early June | 25 August | 3 | Bearberry and lingonberry want snow cover |
| Zone 5 | Early May to early June | 15 September | 2–3 | Shelter barrenwort from winter sun |
| Zone 6 | Late April to late May | 1 October | 2 | All species here are reliable |
In zone 3 and cold zone 4, species choice matters more than technique. Many variegated cultivars were selected in mild maritime climates and lose colour and hardiness inland. Stick to documented hardiness for your zone and buy from a nursery at a similar latitude.
Common mistakes
- Planting over live root weeds. Goutweed and quackgrass come straight up through any cover, and you cannot dig them out without lifting the whole bed.
- Spacing too wide. Half the plants does not mean twice the wait, usually three times, because weeds establish in the gaps and compete.
- Landscape fabric under the mulch. It stops your cover's runners from rooting and becomes a weed mat with roots through the weave.
- No weeding in years one and two. That is exactly when the site is most vulnerable. A ground cover is not low maintenance until it has closed.
- No edge against the lawn. Bugleweed, sweet woodruff and creeping jenny walk into turf. Set a hard edge of stone, steel or mown grass.
- Feeding drought-tolerant species. Stonecrop, thyme and bearberry go soft and short-lived on rich soil. Lean is better.
Frequently asked questions
How long do ground cover plants take to stop weeds?
One to three years at the recommended spacing. Fast species such as sweet woodruff, bigroot geranium and white clover usually close in the second season. Slow ones such as barrenwort, wild ginger and lingonberry need three to five years. Until then you weed every three to four weeks.
Should I put landscape fabric under ground cover?
No. Fabric stops your ground cover's runners from rooting, and those are exactly what closes the surface. Within a few years a layer of silt sits on the fabric with weeds rooting through the weave, worse to clear than bare soil. Use plain cardboard and mulch instead.
How many ground cover plants do I need per square metre?
For most perennials 6–12 plants per square metre, which is 30–40 cm (12–16 in) apart. Low species in paver joints go at 20–25 cm (8–10 in), so 16–25 plants. Woody covers such as creeping juniper go at 60–100 cm (24–39 in), so 1–3 plants. Add 15 percent for a staggered grid.
What is the best ground cover for dry shade?
Bigroot geranium, Geranium macrorrhizum. It handles dark and dry better than any other perennial hardy to zone 3, spreads 20–30 cm (8–12 in) a year and divides endlessly. Pennsylvania sedge is a close second and looks more natural under trees. Wild ginger works too, but needs three years.
Can I plant ground cover straight into a lawn?
Not without preparation. Turf roots are dense and take all the water, so a new ground cover is outcompeted. Strip the sod, or smother the area with cardboard and 10 cm (4 in) of chips for a season first. The exception is white clover, which can be overseeded into turf in May after close mowing.
Which ground covers can you walk on?
Creeping thyme, Irish moss and Dutch white clover. Clover takes the most and handles daily traffic. Thyme and Irish moss cope with someone crossing a few times a week, but not a shortcut used every day. None of them takes furniture, play or traffic on wet soil.
Do ground cover plants become invasive?
Some do. Never plant goutweed. Periwinkle near woodland, bugleweed against a lawn, creeping jenny in wet ground and English ivy anywhere in North America are the usual regrets. Treat anything spreading more than 50 cm (20 in) a year as needing a physical edge.
When should I plant ground cover?
Late spring is best everywhere in zones 3–6, because the plant gets a full season to root before winter. Second best is late summer to early autumn in zones 5 and 6, when the soil is warm and rain has returned. In zone 3, frost heave lifts autumn-planted stock that has not anchored.
Want a reminder of when to plant and weed in your zone? It comes with our newsletter, alongside the season's other garden jobs.