Key takeaways
- Make three fixed beds of roughly equal size and only move the crops
- Manure goes on next year's legume bed in autumn
- Lime the brassica bed only if a soil test shows acid soil
- Keep lime and manure apart: never spread them together
- No fresh manure before carrots and parsnips, or they fork
- Give potatoes their own patch, or switch to a 4-year plan
A 3-year crop rotation needs three fixed beds and a simple feeding routine. Each bed grows legumes, then brassicas, then roots and onions, and moves one step every winter. Manure goes on before the legumes, lime only goes on before brassicas if your soil needs it, and the roots get neither.
This guide covers the setting up: bed sizes, what to add to each bed and when, and where potatoes go. For a ready-made sowing list for each bed, see the 3-year crop rotation planting plan.
How a 3-year crop rotation works
Three crop groups take turns in three beds. Each bed grows a different group every year, so no family sits in the same soil two years running.
| Year | Bed A | Bed B | Bed C |
|---|---|---|---|
| Year 1 | Legumes | Brassicas | Roots and onions |
| Year 2 | Brassicas | Roots and onions | Legumes |
| Year 3 | Roots and onions | Legumes | Brassicas |
| Year 4 | Back to year 1 | Back to year 1 | Back to year 1 |
The three groups are:
- Legumes: peas, broad beans, French beans and runner beans.
- Brassicas: cabbage, kale, broccoli, cauliflower, sprouts, swede, turnip and radish.
- Roots and onions: carrots, parsnips, beetroot, onions, garlic, shallots and leeks.
Moving the groups on stops soil pests and diseases building up. It also lets you feed each bed for the crop that’s coming. Legumes enjoy a well-manured bed, leafy brassicas use what’s left, and roots go into leaner soil where they grow straight.
Three fixed beds with paths between. The edges never move. Only the crops shuffle round each year.
How to lay out three rotation beds
Make three beds of roughly the same size, with fixed edges. Equal beds keep the plan simple, because each group always gets the same space.
- Width: about 1.2m, so you can reach the middle from either side without treading on the soil.
- Length: whatever fits your plot. Three beds of 3-4m suit a back garden. On an allotment they can run the full width.
- Paths: 45-60cm wide, or wide enough for a wheelbarrow if you’ll be barrowing manure.
- Edges: timber boards, old scaffold boards or brick all work. Bare soil beds are fine too if you mark the corners.
Label each bed A, B and C with a stake or a painted board, and keep a sketch of what grew where. If you’re building from scratch, the guide to raised bed gardening for beginners covers materials and filling.
Which bed starts as what? Put brassicas in the bed with the firmest, best-drained soil in year one. Put legumes in the bed you can manure this autumn. Roots go in whatever’s left, as long as it isn’t freshly manured.
When to add manure, lime and compost
Each bed gets a different treatment in the autumn before its year. Here’s the routine in one table.
| Next year’s crop | What to add | When |
|---|---|---|
| Legumes | Well-rotted manure, spread on the surface or forked in | October to November |
| Brassicas | Lime, only if a soil test shows acid soil | Autumn or winter, well before planting |
| Roots and onions | Nothing extra. No fresh manure | Just clear and level the bed |
| All three beds | Garden compost as a mulch | Autumn or early spring |
Manure before legumes
Spread a good layer of well-rotted manure on next year’s legume bed in autumn. Winter rain and worms work it in for you. The peas and beans grow well in it, and the brassicas that follow benefit from what’s left. Only use manure that has rotted down to a crumbly, earthy mix. The guide to animal manures compared explains the different types and how strong each one is.
Lime before brassicas, only if needed
Brassicas grow best in soil that isn’t acidic, and lime makes clubroot less likely to take hold. But most garden soils don’t need lime every time. Test first with a simple kit. If the soil is acidic, spread garden lime on next year’s brassica bed in autumn or winter, following the pack rate for your soil type. The garden lime guide covers the types and amounts.
Gardener’s tip: Never spread lime and manure on the same bed at the same time. They react and the manure loses much of its goodness. In this rotation they always go on different beds, which keeps them apart.
Nothing extra for roots
Carrots and parsnips fork and split in freshly manured soil. The roots bed had its manure two years earlier, before the legumes, which is just right. Rake it to a fine, stone-free finish before sowing.
Autumn is feeding time. Manure goes on next year’s legume bed, and lime, if a test says you need it, goes on a different bed entirely.
How no-dig beds fit a 3-year rotation
No-dig beds still rotate, but the feeding is simpler. Instead of manuring one bed a year, spread a few centimetres of compost or well-rotted manure over every bed each autumn or winter. Don’t dig it in. Worms do that job.
On no-dig beds every bed gets a compost blanket each autumn. The crop groups still move one bed along as usual.
The crop order stays exactly the same: legumes, then brassicas, then roots. Pests and diseases build up just as they would in dug beds if one family stays put. Mulched beds also make it easy to spot and pull any stray potatoes or self-sown plants that would muddle the rotation.
If you’re new to the method, the no-dig gardening guide explains how to start a bed from grass or weeds.
Where do potatoes fit in a 3-year rotation?
Potatoes are the awkward crop in a three-bed plan. They take a lot of space and share blight with tomatoes. There are three good options.
A separate potato patch. Grow potatoes on a fourth patch outside the three beds, and move it to fresh ground each year. This is the simplest answer on an allotment.
Sacks or tubs. On a small plot, grow potatoes in large sacks of compost. Tip the old compost onto a different bed each year as a mulch, but not onto ground where you’ll grow tomatoes.
Move up to four beds. If you grow lots of potatoes, the 4-year crop rotation gives them their own bed in the cycle.
A separate potato patch at the back keeps spuds out of the three-bed cycle. Move it to fresh ground each year.
Crops that fit any bed
Some quick crops can fill gaps in any of the three beds. They don’t share serious soil problems with the main groups, so they won’t upset the rotation.
- Lettuce, rocket and other salad leaves
- Spinach and chard
- Courgettes, squash and pumpkins, given plenty of compost
- Sweetcorn
- Annual herbs such as basil and coriander
Use them as catch crops: quick sowings in the gaps before a main crop goes in or after one comes out. For the full family list, the guide to plant families for crop rotation sorts every common vegetable into its group.
Legumes on the left, brassicas in the middle, roots and onions on the right. Sort crops by family and the rotation sorts itself.
What if a bed already has clubroot?
Rotation keeps clean ground clean, but it won’t clear an infected bed. Clubroot spores survive in the soil for many years, much longer than a three-year break.
Swollen, knobbly roots mean clubroot. Bag them for the bin and keep brassicas off that bed for as long as you can.
If you lift brassicas with swollen, knobbly roots, keep brassicas off that bed for as long as you can. Raise transplants in pots of fresh compost so they go in with a strong root system. Choose resistant varieties such as cabbage ‘Kilaton’ or cauliflower ‘Clapton’. Liming acid soil helps slow the disease too. The club root guide has the full picture.
Bag diseased roots for the household waste. Never put them on the compost heap.
Common mistakes with a 3-year rotation
Spreading lime and manure together. They react, and the manure loses much of its nitrogen. Keep them on different beds or several months apart.
A quick photo of each bed every autumn is the easiest rotation record there is. Next winter you’ll know exactly where everything goes.
Liming without testing. Lime isn’t a general tonic. Too much on soil that’s already alkaline can lock up nutrients. Test first.
Manuring the roots bed. Fresh manure makes carrots and parsnips fork. The roots bed gets nothing extra.
Moving the bed edges. The crops rotate, not the beds. Fixed edges make the plan easy to follow year after year.
Forgetting what grew where. Photograph each bed every autumn and keep a simple sketch. It’s the one habit that keeps a rotation on track.
3-year rotation calendar for soil jobs
| Month | Rotation and soil jobs |
|---|---|
| January | Check your plan and order seed for each bed |
| February | Test soil pH if you haven’t this winter |
| March | Mulch beds with compost if not done in autumn. Sow broad beans and peas |
| April | Plant onion sets. Sow carrots and beetroot in the roots bed |
| May | Plant out brassicas firmly and net them |
| June | Plant out runner and French beans |
| July | Clear finished crops and sow quick salads in the gaps |
| August | Lift onions and garlic. Note what grew where |
| September | Clear the legume bed, leaving bean roots in the soil |
| October | Spread manure on next year’s legume bed |
| November | Lime next year’s brassica bed if your soil test says it’s acidic |
| December | Sketch next year’s layout and move each group one bed along |
Once the beds are set up, the growing veg hub has guides to every crop that goes in them. For seed lists and varieties bed by bed, read the 3-year crop rotation planting plan next.
Frequently asked questions
How does a 3-year crop rotation work in a UK garden?
Three beds take turns growing three crop groups. One bed grows peas and beans, one grows brassicas such as cabbage and kale, and one grows roots and onions. Each winter, every group moves one bed along. After three years, each bed is back where it started.
Where do potatoes fit in a 3-year rotation?
Best on a separate patch outside the three beds. Move that patch to fresh ground each year, or grow potatoes in sacks. If you want potatoes inside the cycle, a 4-year rotation gives them a bed of their own.
When do you lime in a 3-year rotation?
Only on next year’s brassica bed, and only if your soil is acidic. Test the soil first. If it needs lime, spread it in autumn or winter, well before planting, and follow the pack rate for your soil type.
Where do you put manure in a 3-year rotation?
On the bed that will grow peas and beans next year. Spread well-rotted manure in autumn. The cabbages that follow benefit from what’s left, and by the time roots go in there’s no fresh manure to make them fork.
Is a 3-year rotation enough to prevent club root?
It helps keep clean ground clean, but it won’t cure an infected bed. Clubroot spores last in soil for many years. On infected ground, grow brassicas elsewhere, raise them in pots before planting out, or choose resistant varieties.
Does crop rotation still matter in no-dig beds?
Yes, no-dig changes the feeding, not the need to rotate. Pests and diseases still build up when one family stays put. Mulch every bed with compost each year and keep moving the crop groups as normal.
Our team produces practical UK gardening guidance from source research, contributor records and established horticultural practice. Editorial standards are overseen by Matt W.
