Almost everybody who starts growing food starts by digging, and digging is the hardest, slowest and least effective way to begin. It is heavy work, it brings buried weed seed to the surface where it germinates, and it damages the structure and the life of the soil you are trying to build.
The alternative takes an afternoon, needs no tools beyond a wheelbarrow, and you can plant into it the same day.
Where to put it
The decision that most determines whether this works, and the one people give the least thought to.
Watch the sun before you commit. Look at the spot at nine, at noon and at four, and note when it is in shade. Most gardens have less full sun than their owners think, and the sunniest spot is often not where the lawn is.
Proximity beats size. A small bed by the back door gets weeded, watered and picked. A large one at the bottom of the garden gets visited on Sundays and gives up by August.
South facing is ideal, and east or west facing works. A north-facing spot in the shadow of the house is not worth the effort for fruiting crops, though it will grow leaves.
How big
Smaller than you want, for the first year.
The universal beginner error is starting with more ground than there is time to look after, and a bed that has gone to weeds by July is discouraging in a way that puts people off entirely.
- 1.2 metres wide is the standard, because you can reach the middle from either side without stepping on it. Never walk on a growing bed: compaction is what you spent the afternoon avoiding.
- Any length you like. Three or four metres is a sensible first bed.
- Paths at least 40 centimetres, wider if you use a wheelbarrow. Cardboard and woodchip makes a perfectly good path.
- One bed the first year. Add a second in the second year, when you know how much time you actually have.
A bed of 1.2 by 4 metres is roughly five square metres, which will grow a genuinely useful quantity of food and can be tended in twenty minutes a week.
The no-dig method
The whole process, on grass, in an afternoon.
- Cut the grass short or trample it flat. Do not remove it: it is going to rot down and feed the bed.
- Water the ground if it is dry, because it will be hard to wet later.
- Lay cardboard over the whole area, overlapping every joint generously, at least 15 centimetres. Any gap is where grass comes through.
- Remove all tape, staples and plastic labels. Plain brown cardboard, no glossy print.
- Wet the cardboard thoroughly.
- Pile compost on top, 10 to 15 centimetres deep. More if you have it.
- Rake it level.
- Plant into it straight away.
That is the whole thing. The cardboard excludes light, the grass and annual weeds die and rot, the worms pull the organic matter down, and by the second season the cardboard has gone and you have soil.
Why it works better than digging: you have not inverted the soil, you have not brought buried weed seed to the surface, you have not destroyed the fungal networks and worm channels, and you have added a layer of fertility on top which is where roots feed anyway.
Plant into the compost layer. Small plants and transplants go straight in. For seeds, a fine layer of compost on top gives a good seedbed. For potatoes, lay them on the cardboard and cover with compost.
What to put on top
The one real cost, and there are cheap routes.
Well rotted matters. Fresh manure scorches plants and can carry weed seed; anything still recognisable needs another year in a heap.
Start a compost heap on the same day you start the bed. It is the input that makes the whole system free from year two onwards, and it takes a year to get going. See soil and compost in this domain.
Edges or no edges
You do not need them, and a bed without sides is cheaper, easier to make and easier to widen.
Sides are worth it if: the ground slopes, you want the bed higher for easier access, or you are on a path or hard surface.
If you use them: untreated timber, scaffold boards, or anything you have. Avoid old railway sleepers, which may be creosoted, and be aware that treated timber is a judgement call for a food bed.
Sides harbour slugs, which is the honest downside, and they rot and need replacing.
What to expect in year one
Honesty here saves discouragement later.
- Year one is decent. The compost layer is fertile and most crops do well.
- Year two is better, because the cardboard has gone, the worms have worked, and the soil underneath has begun to change.
- By year three it is a different piece of ground, and this is not gardening romance, it is visible.
- Slugs will be a problem in year one, because you have created a damp organic layer next to grass. It improves.
- You will not feed a household. Five square metres is a genuine contribution and it is not self-sufficiency, and understanding the arithmetic early matters. See what to grow for calories in this domain.
- Something will fail. In every season, something bolts, gets eaten or does not germinate. That is normal and it is not you.
Top the bed up with a few centimetres of compost each winter and that is essentially the entire maintenance regime.
Perennial weeds
The one thing cardboard does not simply solve.
Annual weeds and grass die under cardboard. Perennials with deep or spreading roots do not.
- Couch grass, bindweed, ground elder, docks, dandelion, horsetail. These push through joins and edges and come up through the compost.
- Double or triple the cardboard over a badly infested area, and extend it well beyond the bed.
- Then be persistent. Pull every shoot that appears, as soon as it appears, and keep doing it. Repeatedly removing top growth exhausts the root eventually.
- Bindweed and horsetail take years. Accept that, and keep pulling rather than expecting a solution.
- Do not rotavate. Chopping a perennial root into fifty pieces gives you fifty plants, and this is how a manageable problem becomes a permanent one.
- Do not put perennial roots in the compost heap. Drown them in a bucket of water for a few weeks first, or bin them.
If you have no garden
Most of this still applies at a smaller scale.
- Containers. Anything over about 30 centimetres deep. Buckets with holes drilled, builders' trugs, old compost bags stood upright and rolled down. Potatoes, salad, beans, herbs and tomatoes all do well.
- Water far more often. Containers dry out in a day in summer, and this is the main reason container growing fails.
- A windowsill grows herbs, salad leaves and sprouted seeds year round. See sprouting seeds, which needs no light at all.
- An allotment. Waiting lists are long in some areas and short in others, and it costs very little. Get on the list now, because the list is the constraint rather than the money.
- Shared ground. A neighbour with a large garden they cannot manage is a common arrangement and a good one. See community and mutual aid.