Crop rotation is simply not growing the same crops in the same place every year.
The reason it’s important to the home gardener is:
Specific soil nutrients are depleted when the ground is planted with the same type of plants year after year.
Pests and diseases accumulate quickly if the same type of plants is grown in the same ground year after year.
The result is that very quickly you will see a reduction in the quality and yield if you don’t practice some form of crop rotation.
A Simple Crop Rotation Plan
Divide your growing space into at least 4 areas, identify the crops you want to grow and then keep plants of the same type together in one area. Change the type of plants grown in each area every year and try not to grow plants from the same type in the same place for 3 years (i.e. only replant in the same place in the 4th year).
Group your plants into the following categories:
Carrots, Beetroot, Chicory, Artichoke (Jerusalem), Parsnips, Potatoes and Salsify.
Brussels Sprouts, Broccoli, Cabbage, Cauliflower, Kale, Kohl Rabi, Radish, Swede and Turnip.
Sweet corn, Tomato, Spinach, Pea, Onion, Marrow, Lettuce, Leek, Endive, Cucumber, Celery, Celeriac, Peppers, Beans and Aubergine.
Grow plants from the same groups together and change their position in the plot annually.
It is best to use at least a four-year rotation system because this is the number of years it takes for most soil-borne pests and diseases to decline to harmless levels. If your beds are divided into four groups, this means that members of each plant family won’t occupy the same spot more than once in a four-year period.
It is possible to create a more sophisticated crop rotation system by dividing your crops into more groups. You can then apply the same principles of planting the same plants together than not planting the same group in the same place until the third year. To help you do this we have colour coded the Veg Planner Wall Chart indicating which plants belong to the same more sophisticated groups.
Further Handy Tips
Avoid planting root vegetables such as carrots and parsnips on areas that have been heavily fertilised or manured. This will cause forking of the roots and if the soil is high in nitrogen from fertilisers such as pelleted chicken manure you will get lots of lush foliage and relatively little root growth.
Sow parsnip on an area that has housed demanding crops (such as brassicas) the previous season. The previous crop will have broken down the heavy soil effectively preparing for the root crops.
Sow crops such as cabbage, cauliflower and kale on soil previously used for beans and peas. The peas and beans (legumes) fix nitrogen in the soil which will help the second crop. Potatoes also love nitrogen-rich soil, but should not be planted alongside brassicas (Cabbages etc) because they like different pH levels.
Some crops are very quick growing and hence do not need to be strictly rotated these include radishes and lettuce use these as catch crops or to fill gaps in your rotation plan.