Crop rotation plays an important part in ensuring healthy plants and great yields. There are some perennials that this does not apply to, asparagus, artichokes, rhubarb etc.
If you have an allotment you have plenty of room to practice crop rotation but it is possible even with a lot less available space. For instance, in our garden we have three areas for growing produce, one border and two 2 x 1 meter raised beds.
It makes perfect sense to switch planting areas each year. By doing this you prevent your soil being exhausted by the same plants depleting the same nutrients.
Many systems exist but they all pretty much do the same thing i.e., groups certain vegetables together and then rotate said groups over a period of years, usually three or five.
Year 1 would be: peas, beans and fruiting vegetables
Year 2 would be: brassicas
Year 3 would be: roots, onions and leaves
|Sugar Snap Peas
The benefits of planting the Year 1 group is that the peas and beans have the ability to absorb nitrogen from the air and store it in nodules on their roots. If you leave the roots in the ground after harvest, the following year's crop will benefit from the added nitrogen.
It makes perfect sense to rotate the Year 2 group into the Year 1 space because they are all nitrogen hungry and they are the group that is most susceptible to clubroot. By rotating you lessen the risk of this.
Year 3 come under the root veg badge and they mostly have a low nitrogen requirement and therefore ideal for following in Year 2's footsteps.
If you have plenty of space available you could follow a five year crop rotation plan and that would be:
Year 1 - brassicas
Year 2 - peas and beans
Year 3 - potatoes and fruiting vegetables
Year 4 - the onion family
Year 5 - root and stem vegetables
Squashes, courgettes, lettuce, spinach can be popped in with any group where necessary.