Crop rotation only becomes difficult when it’s approached as a set of rules to memorise. In reality, it’s a simple decision-making process: understanding what a crop does to the soil, then choosing what should follow it.
This guide brings together everything you need to know about what to plant after each crop on a UK allotment, using a clear, practical rotation system that works on real plots. It’s not about perfection or rigid diagrams. It’s about keeping soil healthy, reducing problems naturally, and making the allotment easier to manage year after year.
If you ever find yourself asking “what should go in this bed next?”, this is the page that answers it.
How crop rotation actually works on an allotment
Every vegetable affects the soil differently. Some take a lot out of it. Some give something back. Some compact it. Some loosen it. Crop rotation works by balancing those effects over time rather than letting one problem build up.
On most UK allotments, rotation revolves around crop families, not individual vegetables. Once you understand how those families behave, the logic becomes straightforward.
The sections below explain what should follow the four main crop groups used in almost all allotment rotation systems.
What to plant after potatoes
Potatoes are heavy feeders and they disturb the soil more than most crops. They’re excellent for clearing ground, but they leave beds low in nutrients.
The best crops to plant after potatoes are those that help rebuild soil fertility or make efficient use of the loosened structure. Legumes such as peas and beans are ideal, followed by brassicas if fertility is topped up.
Planting another heavy feeder immediately after potatoes usually leads to disappointing results.
→ Read the full guide: What to plant after potatoes
What to plant after peas and beans
Peas and beans belong to the legume family and play a unique role in rotation. They improve soil fertility by fixing nitrogen, which benefits the crops that follow them.
Because of this, legumes are best followed by crops that need richer soil, particularly brassicas and leafy vegetables. Used properly, peas and beans help reset the balance of an allotment without added fertiliser.
Repeating legumes in the same bed too soon reduces those benefits.
→ Read the full guide: What to plant after peas and beans
What to plant after brassicas
Brassicas are demanding crops. They stay in the ground for a long time and take a lot from the soil. If rotation slips here, problems like pests, disease, and declining yields tend to follow.
After brassicas, the priority is recovery. Legumes are the most effective follow-on crop, helping to restore fertility, while potatoes can be used to break up compacted soil and reset the bed.
Repeating brassicas in the same area is one of the most common rotation mistakes on allotments.
→ Read the full guide: What to plant after brassicas
What to plant after onions and other alliums
Onions and other alliums are lighter feeders, but they still shape how a bed performs next. They leave soil fairly firm and tidy, which suits certain follow-on crops better than others.
Brassicas and potatoes both work well after onions, while repeating alliums increases the risk of disease and pest build-up over time. Even though onions seem low-impact, they still need rotating like any other crop.
→ Read the full guide: What to plant after onions
How this fits into a simple crop rotation system
Most allotment crop rotation systems can be reduced to a clear cycle:
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Potatoes
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Legumes (peas and beans)
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Brassicas
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Roots and alliums
In a four-bed setup, each group moves on one position each year. In three-bed systems, potatoes are often grouped with other heavy feeders, followed by legumes and then brassicas or roots.
The exact structure matters less than the principle: don’t grow the same crop family in the same place year after year.
What if your allotment doesn’t fit neatly into a system?
Many allotments aren’t textbook plots. Beds change shape. Crops overlap. Space is tight.
In those cases:
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rotate crop families rather than individual vegetables
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prioritise moving problem crops like brassicas and potatoes
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accept that partial rotation is still effective
Rotation doesn’t need to be perfect to work. It just needs to be consistent.
Planning crop rotation without losing track
Most rotation problems don’t come from a lack of knowledge. They come from memory. After a season or two, it’s easy to forget what was grown where, especially when crops overlap or beds are reused quickly.
Being able to see:
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what was planted in each bed
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what should follow next
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how crops move year to year
makes rotation far easier to stick to long term and prevents accidental repetition.
Final thoughts
Crop rotation isn’t about strict rules or complicated charts. It’s about understanding how crops affect the soil and making better decisions as a result.
Once you know what to plant after each crop, rotation stops being something you worry about and starts being something that quietly improves your allotment in the background.
Use this page as your reference point whenever a bed becomes free. Everything else builds from here.