What is crop rotation? The secret expert gardeners use to guarantee a successful bumper crop of vegetables every year

We know what you’re thinking: what is crop rotation?

Well, it’s as simple as it sounds. Crop rotation is the practice of rotating crops belonging to specific groups around a vegetable bed from year to year to avoid growing vegetables from the same group in the same spot. It's a staple technique, whether you're learning how to start a small vegetable garden for the first time or you're a seasoned gardener.

Gardeners generally divide these crops into four categories: alliums (like onions, garlic and leeks), root vegetables (such as carrots and turnips), brassicas (like cabbages, broccoli, cauliflower, and kale), plants in the potato family (including tomatoes), and legumes (peas and beans). These groups cover everything from the easiest vegetables to grow to the most challenging and unusual.

'If you thrive on a systematic, logical way of growing, then crop rotation is the ideal method to follow,' says Lucie Bradley, gardening and greenhouse expert from Easy Garden Irrigation. 'It also lets you plan your gardening year when the winter weather is poor and you can’t get out in the garden.

'However, more importantly, crop rotation will result in healthier plants and bigger yields, whilst also making your life easier by reducing problems such as pests and diseases.'

We thought we'd explore the five vegetable categories a little further to understand how crop rotation works.

Lucie Bradley

Encouraged to garden since she was old enough to walk, Lucie has been working in the gardening industry for over 28 years. This has meant she has been lucky enough to talk to both amateur and professional gardeners every day of the week and is always learning. She believes you can never know everything about gardening as it constantly evolves.

What you'll need

• A notepad to plan your crop rotation layout
• Plant labels like these bamboo plant markers from Amazon
• Vegetable seeds like this selection of vegetable seeds from Thompson & Morgan
• Gardening gloves like these Verve Leather Gardening Gloves from B&Q

The four crop groups

1. Alliums

Above all else, crop rotation dramatically reduces the risk of garden plant pests and diseases spreading from one year's batch of crops to the next.

Alliums like onions, leeks and garlic are natural pest repellents, so growing them in different areas of a vegetable patch can reduce the number of critters lying in wait for future crops.

'This group is generally resistant to pests and diseases, so they make great crops to prevent the build-up of soil-borne pests,' explains Lucie.

2. Brassicas

Next up are brassicas, which generally follow legumes in crop rotation. Brassicas include a wide range of vegetables, from broccoli and Brussels sprouts to cabbages, kale and cauliflower.

'Vegetables within this group benefit from nutrient-rich soil as they are heavy feeders, so they're great to be planted after you have grown legumes,' says Lucie.

Sounds similar to companion planting ideas, right? Well, it is — and one of the main benefits of crop rotation is its ability to boost soil health for future crops.

'Different crops will require different nutrients or soil microbes, so rotating your crops often can help to ensure that the soil does not become depleted over time,' explains Graham Smith MCIHort, gardening expert at LBS Horticulture. 'For example, growing corn can take a lot of nitrogen from the soil, and growing beans after this can help to return the nitrogen.'

3. Root vegetables

Now, onto the root vegetables. Whether you're learning how to grow potatoes, carrots or turnips, these ground-dwellers can deplete the soil after a season of growth.

'These vegetables can be prone to specific pests such as carrot root fly and will drain the soil of certain nutrients,' says Lucie.

For this reason, Lucie says root vegetables are best followed by legumes like peas and beans, which will nourish your vegetable patch with nutrients again.

4. Legumes

Speaking of legumes, these nitrogen-fixers are one of the most advantageous crop groups — so if you've been thinking about growing broad beans for the first time, consider building them into your crop rotation plan.

'Although these types of plants can be grown in the same location year after year, including them in crop rotation will benefit your other crops as they will add nitrogen back into the soil, improving its fertility ready for the crops which will follow them,' says Lucie.

5. Potato family

Last, but not least, is the potato family. Believe it or not, this group includes tomatoes, peppers and aubergines as well as our classic spuds.

Aubergines and peppers, however, are less prone to diseases than potatoes and tomatoes (which can easily fall victim to blight), so gardeners generally agree that they can be grown anywhere in the cycle.

As for potatoes and tomatoes, they're generally grown after brassicas and before legumes, onions and root vegetables.

How does crop rotation work?

The first step in setting up crop rotation is dividing up your vegetable bed. Usually, gardeners divide them into three or four sections, depending on the length of the cycle you're aiming for.

‘Crop rotation is usually done on a three- or four-year cycle,’ explains Graham Smith MCIHort, gardening expert at LBS Horticulture. ‘In a four-year crop rotation cycle, legumes are added.'

Then, you’ll need to think about the layout of your vegetable bed, and what vegetable you’ll be growing in each section.

Graham says an example layout for the first year could look like this:

• Section one: Potatoes
• Section two: Onions and roots
• Section three: Brassicas
• Section four: Legumes

After you’ve harvested all of your first-year crops, you can start thinking about the layout of your vegetable bed for the following year. It’s simple — you just need to rotate everything around.

Assuming you followed Graham’s example layout, your vegetable bed would look like this in its second year:

• Section one: Onions and roots
• Section two: Brassicas
• Section three: Legumes
• Section four: Potatoes

Wondering where salad crops fit into all of this? Well, Graham says there's plenty of room for them, but they don't adhere to the same rules as the other crop groups.

‘You can make the most of the growing space that you have by under- or inter-planting your main crops with fast growing smaller crops, such as salad leaves,’ Graham says.

It's also a fantastic way to reduce weeds naturally.

FAQs

Is crop rotation easy for beginners?

Gardening expert Lucie is a huge advocate for crop rotation, for gardeners of all levels of experience.

'Crop rotation is a great way for new gardeners to make the most of their kitchen garden or allotment plot,' she says. 'Crop rotation teaches you about the relationships between different plants and companion planting, and means your gardening will be more about enjoying your plants and less about ‘fire fighting’ against pests and diseases.'

What is a simple definition of crop rotation?

In a nutshell, crop rotation is the practice of, well, rotating crops belonging to four distinct categories around a vegetable patch from year to year to reduce the spread of pests and diseases and boost soil health.

It's as simple as that! Using our guide to crop rotation, you can start planning your vegetable garden for 2025 and beyond.