Key takeaways
- Set slabs on edge, all leaning the same way, with about half to two-thirds buried
- Keep planting gaps narrow, about 2-5cm, so plants sit snug and dry
- Backfill with a lean mix of mostly grit and sharp sand with a little loam, never rich compost
- Reclaimed paving or slate offcuts make good, affordable crevice stone
- Plant small plugs, not big pot-grown alpines, and finish with a grit top dressing
A crevice garden is a bed of stone slabs set on edge, packed closely together, with plants growing in the narrow gaps. It looks like a slice of mountainside and it’s one of the best ways to grow alpines in a wet British climate.
This guide covers choosing stone, building the bed, the lean planting mix, the best plants and care through the year. If you’d prefer a looser look with big rocks part-buried in a bank, see our guide on how to build a rockery. A crevice garden is the more modern, compact take on the same idea, and it fits nicely into a front garden or a small bed.
What is a crevice garden and why do alpines love it?
It’s a bed of upright or steeply angled slabs, all leaning the same way, with planting gaps of about 2-5cm. A good part of each slab is buried, so the stone is anchored well below the surface. The style was popularised by Czech rock gardeners and is now seen in botanic gardens across Europe.
Alpines thrive in those gaps for three reasons:
- Sharp drainage. Rain runs down the stone faces and drains away fast.
- A cool root run. Roots follow the slabs down into cool, moist grit below the surface.
- Dry crowns. Each plant sits on stone and grit rather than wet soil. A dry crown is the key to getting alpines through winter.
Alpines snug in narrow gaps between the stones. Each crown sits on grit and stone, never on wet soil.
Where to find stone for a crevice garden
Reclaimed paving is the easiest and cheapest option. Sandstone or concrete slabs can be split into strips, and old sandstone already looks weathered. Ask on local selling sites or at a reclamation yard.
Slate offcuts from roofing merchants suit very narrow gaps and give crisp, dark lines. You can also buy new sandstone or limestone from a local quarry or stone merchant.
Whichever you choose, stick to one type of stone per bed, so it reads as a single outcrop. Avoid water-worn limestone, which comes from protected limestone pavements.
Reclaimed paving strips and slate offcuts. Pick one stone type and stick with it.
How to build a crevice garden step by step
Allow a long weekend for a small bed, plus time for it to settle.
- Mark out and dig. Dig out the area about 25-30cm deep. On heavy clay, fork the base and add a layer of coarse gravel. If water still sits in the hole after rain, sort that out first: our soil drainage and structure guide explains how.
- Split the slabs. Score each slab with a bolster chisel, then snap it over a length of timber into strips. Wear safety glasses and gloves. Expect a few breakages.
- Set the first row. Stand your tallest strips along the centre, all leaning at the same steep angle, with about half to two-thirds buried. Keep them parallel.
- Work outwards. Add rows either side, leaving gaps of about 2-5cm. Fill each gap with gritty mix as you go, pushing it down with a cane so there are no air pockets.
- Top dress. Spread a few centimetres of fine grit over all the soil and tuck it under the slab edges.
- Let it settle. Water the bed well, then leave it for a week or two before planting. A finished slab shouldn’t move when you lean on it.
The big mistake is laying the stone flat or nearly flat. Then rain sits in the gaps instead of running down, and you’ve built crazy paving with plants in the joints. The upright angle is what makes a crevice garden work.
Setting a strip on edge. Bury a good part of each one so it stays firm through frost and wet.
Most of each slab is hidden. The buried part keeps it steady and leads roots down to cool, moist grit.
The best planting mix for a crevice garden
Use a lean, gritty mix: mostly horticultural grit and sharp sand, with just a little loam. Two parts grit, one part sharp sand and one part loam is a good recipe. John Innes No.1 can stand in for the loam if you can’t get it loose.
It looks very poor, and that’s the point. Alpines come from mountains where food is scarce and water drains away fast. Grown lean, they stay tight and tough. In rich compost they grow soft and leafy, then rot when the winter rain comes.
Don’t add multipurpose compost or fertiliser. The grit top dressing matters as much as the mix underneath: it keeps each plant’s neck clear of damp soil and stops rain splashing mud into the rosettes.
Mostly grit and sharp sand with a little loam. No compost and no fertiliser.
Best alpines for a UK crevice garden
Start with tough, reliable plants, then try the fussier ones once the bed has settled. Buy small plugs or 9cm pots: big rootballs won’t fit in narrow gaps.
| Plant | Looks | Good to know |
|---|---|---|
| Saxifrages (silver or encrusted types) | Silver rosettes, white or pink sprays in spring | Love crevices and grow into neat cushions |
| Sempervivum (houseleeks) | Fleshy rosettes in green, red and purple | Almost indestructible in sun |
| Dianthus alpinus and other alpine pinks | Low grey-green mats, pink flowers | Full sun and sharp drainage |
| Draba | Tight green buns, yellow flowers in early spring | Among the first to flower |
| Armeria (thrift) | Grassy tufts, pink pompom flowers | Tough and good near the coast |
| Phlox douglasii | Low mats smothered in flowers in late spring | Give it a sunny spot |
| Lewisia cotyledon | Fleshy rosettes, striped flowers in pink and orange | Plant on its side in a crevice so water runs off the crown |
You’ll find more on these in our guides to growing lewisia and growing dianthus. Trickier plants such as the spring gentian (Gentiana verna) are lovely, but they’re a challenge to keep.
Crevice garden care month by month
Autumn is a great time to build, as the stone settles before winter. Spring builds work well too, but water new plants more in their first summer.
| Month | Jobs |
|---|---|
| January | Lift wet leaves off the plants after storms. Don’t water |
| February | Re-firm any plants lifted by frost and top up grit around their necks |
| March | Start planting once the worst weather has passed |
| April | Main planting month. Water new plugs if it’s dry |
| May | Peak flowering. Water first-year plants in dry spells |
| June | Deadhead pinks and phlox. Pot up sempervivum offsets |
| July | Water first-summer beds well in long dry spells |
| August | Established beds rarely need water. Shade lewisias in a heatwave |
| September | A second chance to plant. Order stone if building in autumn |
| October | A good month to build a new bed |
| November | Clear fallen leaves every week. Wet leaves rot cushions fast |
| December | Prop a pane of glass over lewisias in very wet areas |
Why a crevice bed suits wet British winters
Most alpines don’t die of cold. They die of winter wet sitting around the crown. They’re built for frost and snow, but not for months of mild, soggy soil.
In an ordinary bed or rockery pocket, the soil can stay wet from November to February. In a crevice garden, the stone and grit shed water fast and keep the crown dry. That’s why a crevice bed often keeps more alpines alive through a wet winter.
Common crevice garden mistakes
- Laying slabs flat. The bed stops shedding water. Stand the stone up and bury a good part of each slab.
- Using rich compost. It holds winter wet and makes soft growth. Keep the mix lean and gritty.
- Making gaps too wide. A wide gap becomes a soil pocket that slumps and grows weeds. Wedge a stone sliver into any gap that looks generous.
- Planting big pot-grown alpines. A large rootball won’t fit, so people widen the gap and leave air pockets. Buy plugs and let them grow into the stone.
- Leaving fallen leaves. A wet leaf lying on a cushion can rot it. Clear the bed weekly in autumn.
Left: a narrow gap holds the plant snug. Right: a wide gap slumps, stays wet and fills with weeds.
No room for a bed? Our guide to alpine troughs and containers shows how to grow the same plants on a patio, and there are more ideas on the garden design hub.
Frequently asked questions
What is a crevice garden?
A crevice garden is stone slabs set on edge with narrow planting gaps between. The slabs are part-buried and lean the same way, like a natural rock outcrop. Alpines root down between the cool stone faces into gritty soil, with their crowns kept dry. It suits wet British winters better than a flat bed.
How wide should crevice garden gaps be?
About 2-5cm, just wide enough for a small plug plant. Narrow gaps hold the plant firm, send rain straight down and leave little room for weeds. Much wider than that and the gap behaves like an ordinary soil pocket, holding winter wet.
What angle should crevice garden slabs be set at?
Upright or leaning steeply, never flat. Set every slab at the same angle so they run parallel, like layers of rock pushed up from below. Bury about half to two-thirds of each one so it stays firm. Slabs laid flat just make crazy paving with plants in the joints.
What soil mix does a crevice garden need?
A lean, very free-draining mix of grit, sharp sand and a little loam. Two parts grit, one part sharp sand and one part loam is a good starting point. John Innes No.1 can stand in for the loam. Don’t add multipurpose compost or fertiliser.
Which alpines grow best in a UK crevice garden?
Saxifrages, sempervivums, alpine pinks, draba and thrift are the most reliable. Phlox douglasii and Lewisia cotyledon do well once the bed is settled. Lewisia is especially happy on its side in a crevice, which keeps water out of its crown.
Can I build a crevice garden from old paving slabs?
Yes, reclaimed sandstone or concrete paving works well. Score and split the slabs into strips with a bolster chisel and club hammer. Wear safety glasses and gloves. Stick to one type of stone so the bed looks like a single outcrop.
Our team produces practical UK gardening guidance from source research, contributor records and established horticultural practice. Editorial standards are overseen by Matt W.
