Crop rotation for allotments
Move your vegetables around so the same family doesn't grow in the same spot two years running. Here's the simple system.
Why bother rotating?
Every vegetable family takes different nutrients from the soil and leaves different problems behind. Growing cabbages in the same bed year after year lets clubroot spores build up in the soil. Once it's there, it can persist for 20 years. The same goes for white rot with onions and blight with potatoes.
Rotation solves three problems at once:
- Disease prevention — soil-borne pathogens can't build up when their host crops keep moving
- Balanced nutrients — legumes add nitrogen, brassicas use it, roots are light feeders. Moving them around keeps the soil in balance
- Better yields — crops grown in fresh ground consistently outperform those planted in tired soil
The four rotation groups
Split your vegetables into four families. Each group follows the other around your plot in a four-year cycle. If you have four beds, each group gets a bed. If you have one bed, divide it into quarters.
How the 4-year cycle works
The order matters. Legumes go first because they fix nitrogen in the soil. Brassicas follow because they're hungry for nitrogen. Roots come next as light feeders that benefit from the residual fertility. Alliums and potatoes round it off, and you'd typically add compost or manure before this group to reset the bed.
In year 5, you're back to year 1. The cycle repeats.
Crops that stay put
Not everything rotates. Perennial crops live in the same spot for years and should have their own dedicated patch, outside your rotation beds.
Permanent crops (no rotation needed):
- Asparagus — stays productive for 15–20 years in one spot
- Rhubarb — give it a corner and leave it alone
- Perennial herbs (rosemary, thyme, sage, mint, chives)
- Strawberries — replace every 3–4 years, but not part of the main rotation
Common mistakes
Forgetting that tomatoes are nightshades
Tomatoes, potatoes, peppers, and aubergines are all in the same family (Solanaceae). They share blight and should be treated as one group for rotation purposes. Growing tomatoes where potatoes were last year defeats the point.
Putting potatoes in the same spot every year
Potatoes are the crop most people forget to rotate. They're susceptible to eelworm and blight, both of which build up in the soil. Move them every year without fail.
Ignoring brassica volunteers
That self-seeded kale or sprouting broccoli from last year? It's still a brassica sitting in the brassica bed, keeping clubroot happy. Pull it out if it's in the wrong rotation spot.
Being too rigid
A perfect four-year rotation is the ideal. Real allotments are messy. If you can't manage four groups, even alternating between two — legumes/roots one year, brassicas/alliums the next — is better than no rotation at all.
Making it work on small plots
If you've got a single raised bed or a tiny back garden patch, a full four-bed rotation isn't realistic. Here's how to adapt:
- Divide mentally, not physically. Split one bed into four quarters and rotate within it. It's not as effective as separate beds, but it still helps
- Prioritise the vulnerable crops. Brassicas and alliums suffer most from soil-borne disease. If you can only rotate two groups, make it those
- Use containers for the gaps. Grow tomatoes and potatoes in bags or large pots so they're not using bed space in your rotation
- Don't stress about lettuce and salads. Quick-growing leafy crops like lettuce, spinach, and radishes can slot in wherever there's space. They're not building up serious soil problems
Common questions
Why is crop rotation important?
It prevents soil-borne diseases from building up, balances nutrients naturally, and breaks pest life cycles. Growing the same family in the same spot year after year depletes specific nutrients and lets diseases like clubroot and white rot accumulate.
What are the 4 crop rotation groups?
Legumes (peas, beans), Brassicas (cabbage, broccoli, kale), Roots (carrots, parsnips, beetroot), and Alliums & others (onions, garlic, potatoes, squash). Each group moves to the next bed each year.
Do potatoes and tomatoes count as the same family?
Yes. Both are nightshades (Solanaceae) and share diseases like blight. They should not follow each other in your rotation. Peppers and aubergines are nightshades too.
Can I do crop rotation in raised beds?
Yes. If you only have one or two beds, a strict four-year rotation is harder, but you can divide beds into sections. Focus on never growing the same family in the same spot two years running, and prioritise rotating brassicas and alliums.
Which crops don't need to be rotated?
Permanent crops like asparagus, rhubarb, and perennial herbs stay in one place for years. Give them their own dedicated patch outside your rotation beds.
Related guides
What to grow together and what to keep apart.
Personalised sowing dates for your postcode.
All 40 crops across 12 months at a glance.
New to growing? Start here.
Test and improve your soil before each rotation.
Build soil between rotations with good compost.
Rotation is mostly a planning exercise — you don't need much kit. But a couple of cheap items make it easier to stay organised and catch soil problems before they bite.
Planning & soil testing
Soil pH test kit
~£7A basic liquid or strip test kit that tells you whether your soil is acid, neutral, or alkaline. Essential before rotating brassicas into a bed — they need pH 6.5–7.5 and will struggle in acidic soil.
Test each bed before rotating brassicas in. They need pH 6.5–7.5 — add lime if it's acidic.
Garden planning notebook
~£10Any notebook will do, but a dedicated allotment planner with bed layouts and monthly pages makes it dead simple to record what went where. The single most useful thing for keeping your rotation on track year to year.
View on AmazonWeatherproof bed labels
~£6Cheap metal or plastic labels you push into each bed at the start of the season. Write the crop group and year on them. When February comes around, you won't have to guess what was growing where.
View on AmazonAffiliate links — This guide contains links to Amazon. If you buy through them, we earn a small commission at no extra cost to you. We only recommend things we'd actually use on our own plot.