Autumn is the best moment of the year to start a no-dig bed. Lay cardboard over the grass or the weedy patch you have been meaning to tackle, cover it with a thick layer of compost, and walk away. By March the cardboard has gone, the weeds beneath it have starved in the dark, the worms have stitched compost and soil together, and you sow straight into a surface you never turned over. Six months of doing nothing does what a weekend of digging cannot.
No-dig is not a new idea — it is how every woodland floor has fed itself for a few million years — but Charles Dowding's trial beds in Somerset turned it from a philosophy into a method with measurable results: equal or better yields, far fewer weeds, and a fraction of the labour. This guide covers why it works, how much compost you actually need, how to build a bed from scratch this autumn, what you can sow into it before winter, and the handful of mistakes that make people give up in year one.
- Best time to start September–November, so the bed settles over winter; any month works if you can wait
- Compost depth 10–15 cm over cardboard on a new bed; 2–5 cm on top every autumn after that
- Per square metre One layer of plain brown cardboard and 100–150 litres of compost — a 1 m³ bulk bag covers 7–10 m²
- First sowings Broad beans and round-seeded peas in October–November; everything else from March
Why no-dig works
Soil is not a container for plants; it is a structure. Fungal threads, worm tunnels, root channels and the crumbs that soil bacteria glue together are what let water drain, air move and roots travel. Every time a spade turns it over, that structure collapses, the fungi are cut to pieces, a season's worth of buried weed seed is brought up to the light, and the carbon that held the crumbs together is oxidised into the air. The soil recovers — it always does — but it spends the spring rebuilding what you destroyed instead of feeding your lettuce.
No-dig feeds from the top instead. A layer of compost on the surface is pulled down by worms over the winter, exactly as leaf litter is in a wood, and the soil beneath becomes darker, more crumbly and more open every year without a fork touching it. The practical dividends are the ones people notice first: a fraction of the weeding, because dormant seed stays buried; beds that can be walked beside, planted and sown in wet weather without turning to concrete; and soil that warms and drains faster in spring, which brings the first direct sowings forward by a fortnight. Our guide to preparing soil still applies to what you add; no-dig only changes where you put it.
What you need: cardboard and a great deal of compost
The cardboard is the easy part. Plain brown boxes with the tape and staples removed, laid flat and overlapped by 15 cm so no light reaches the ground — glossy printed board and anything waxed stays out. Its job is temporary: it blocks light for the two or three months the grass and annual weeds need to die, then rots into the worms' lunch.
The compost is the part that stops people. A new bed wants 10–15 cm across its whole surface, and 10 cm on one square metre is 100 litres — so a 3 × 1.2 m bed takes 360–540 litres, roughly half a bulk bag. It does not need to be fine or expensive: home compost, well-rotted manure (a year old, no smell), municipal green-waste compost from the council, spent mushroom compost and leaf mould all work, alone or mixed, and the coarse stuff can go underneath with the finest on top for sowing. Sawdust, fresh woodchip and fresh manure do not belong on the bed itself — the first two rob nitrogen as they rot, the last scorches roots — but woodchip makes the perfect path between beds, where it keeps feet dry and worms busy.
Starting a no-dig bed in autumn, step by step
- Cut everything down and leave the roots Mow the grass short or scythe the weeds to the ground and leave the debris where it falls. Do not dig out the roots — the cardboard and darkness will do that. Only woody shrubs and brambles need removing by hand.
- Lay the cardboard and soak it Cover the whole area, overlapping every edge by a hand's width, and run it 30 cm beyond the bed's edge so nothing creeps in from the sides. Water it thoroughly — wet cardboard lies flat, stays put in wind and starts to rot.
- Spread 10–15 cm of compost Barrow it on and rake it level. Coarser material at the bottom, the finest on top. Firm it lightly with the back of the rake or by treading a board across it — a fluffy bed dries out and slumps.
- Decide on edges and paths A no-dig bed needs no frame at all; a compost mound holds its own shape once it settles. If you want tidy edges, a timber surround turns it into a raised bed, filled the same way. Cardboard and a 5 cm layer of woodchip make the paths.
- Sow something before winter, or nothing The bed can be planted the day it is built — roots pass through the cardboard within weeks. In October and November push in broad beans or round-seeded peas at 5 cm depth, or plant out winter lettuce and hardy salad plants raised in modules. Or leave it bare under the compost and let the worms work.
- In spring, rake and sow — no digging By March the surface is a fine, dark tilth. Rake off any lumps, draw a drill with a cane and sow directly, using the compost itself as the seedbed. From then on the only annual job is a 2–5 cm top-up of compost each autumn after the beds are cleared.
No-dig or dig? An honest comparison
No-dig
Compost on top, soil undisturbed, weeds smothered rather than uprooted.
- Far fewer weeds from the second season; soil structure and worm numbers improve every year
- Beds are workable in wet weather and warm earlier in spring
- Needs a large volume of compost up front, and perennial weeds take a full season or two to exhaust
Digging
Soil turned over each winter, compost worked in, weeds forked out.
- Breaks up a compacted pan or builders' rubble that compost alone cannot cure
- Removes bindweed and couch roots faster, if you sieve every one out
- Brings dormant weed seed to the surface, damages fungal networks and has to be repeated every year
There are gardens where one initial dig is the right call: a plot compacted by machinery, a bed that floods because a hard pan sits below it, or ground full of rubble. Dig once, remove what you find, then never again. Everywhere else, the honest answer from thirty years of side-by-side trials is that the undug bed produces at least as much with less work — and the difference in weeding is not close.
Common mistakes
- Skimping on the compost. Two or three centimetres over cardboard does not smother grass; it feeds it once the card rots. Ten centimetres is the minimum for a new bed, fifteen where the weeds were strong.
- Leaving gaps. Every gap in the cardboard becomes a green tuft by April. Overlap generously, run it beyond the edges, and patch anywhere the compost has slumped and the ground shows.
- Expecting bindweed and couch grass to vanish. Annual weeds and grass die under cardboard in a season; deep-rooted perennials come up through it weakened, not dead. Pull every shoot the moment it shows, without digging, and they are exhausted by the second summer.
- Walking on the bed. The whole method rests on the soil never being compressed. Keep beds narrow enough to reach across — 1.2 m is the usual limit — and stay on the paths.
- Treating no-dig as no-feed. The annual compost top-up is the feed. Skip it for two years and yields slide; there is no need for anything else, though hungry crops in pots and containers still want their liquid feed.
- Losing the rotation. Undisturbed soil makes it easier, not harder, for soil-borne problems to build up under a crop grown in the same place each year. Keep a simple four-bed rotation going exactly as before.
Frequently asked questions
Do I need cardboard if the ground is already bare?
No. On a bed that has been cropped and weeded, cardboard adds nothing — just spread the compost on the cleared surface. Cardboard is only for starting a bed on grass or weeds, or for suppressing a bad infestation of perennial weeds.
Can I sow seeds straight into compost?
Yes, and for most crops the compost surface is a better seedbed than dug soil, because it is level, moisture-retentive and free of weed seed. Fine seed such as carrots, lettuce and onions appreciates a sieved top centimetre if the compost is lumpy; large seed does not care.
Does no-dig mean more slugs?
Less, in practice. A firmed, compost-only surface without lumps, cracks and rotting debris gives slugs nowhere to hide, and Dowding's side-by-side beds consistently show fewer slug problems on the undug side. Keep grass and long weeds away from the bed edges and read our pest guide for the rest.
What should I plant in a new no-dig bed in its first year?
Almost anything, but the crops that revel in a deep compost layer are the greedy ones: courgettes, squash, cucumbers, beans, potatoes and brassicas. Courgettes are the classic first-year crop — their leaves smother anything that finds a gap in the cardboard, and a plant sat in 15 cm of compost needs no further feeding all summer.
No-dig asks for one big effort — finding the compost — and then almost nothing, year after year. Start a single bed this autumn, sow what still can be sown before the days close in, and compare it with your dug beds next summer; most gardeners convert the rest the following autumn. Browse our green manures, broad beans, peas and lettuce for the first sowings, the full range of vegetable and organic vegetable seeds for spring, or read on through our growing guides and the vegetable sowing calendar.
