Crop rotation is the process of growing vegetables in their respective families and moving the families around a plot in a specific sequence so they are not grown on the same piece of land for at least 3 years.
Vegetable Family Table
Vegetable families are classified into mainly 3 types:
|Examples||Cabbage, Broccoli, Cauliflower||Pea, Bean – Broad, Borlotti, Runner, French||Beetroot, Carrots, Onions, Garlic||Potatoes & Tomatoes|
|Notes||Although these are not technically from the same family they are all treated roughly the same||Although technically roots, these are generally grown in their own plot as they are grown in large quantities|
|Soil requirements||Nitrogen rich which may need liming||Well drained but moisture retentive not Nitrogen rich.||Stone-free, fine tilth but not freshly manured as causes forking||high organic matter without lime|
|Soil benefits||None||Leaves behind Nitrogen for following crop||Great for breaking up soil structure||Good at weed surpression & breaking up soil structure|
Crop rotation has been practiced for centuries and has a number of excellent benefits, it helps to avoid the build up of soil-borne pests and diseases that might affect one particular crop; different families leave behind nutrients and can also draw up minerals that help to feed the following crop; and minimises the use of fertilisers which is good for organic cropping.
It is possible to use a 3 year crop rotation programme but if you require a lot of potatoes it is best to split your plot into 4 sections. Potatoes should be grouped with roots in a 3 year plan.
4 Year Crop Rotation Plan
Each bed/area will remain the same number.
|Year 1||Year 2||Year 3||Year 4|
(followed by Leeks or Lettuce in summer)
(Carrots, Beetroot, Onions plus Sweetcorn)
(Cabbage, Broccoli, Sprouts)
(Peas, Beans – Broad, Borlotti, French & Runner)
N.B. If it is very difficult to rotate your crops just try not to grow onions or brassicas in the same spot 2 years running as their soil-borne pests and diseases develop quickly.
There are of course some veg that require permanent beds and do not require moving e.g. Asparagus and rhubarb (many class this as a fruit).
Some vegetables can fit into any crop rotation position, e.g.
- Courgettes & Squash – particularly good with potatoes as they like lots of manure and early/second early potatoes are harvested before these get too large.
- Lettuce is a great catch crop sown in between potato ridges but will fit anywhere.
- Sweetcorn fits well into roots but will do well elsewhere too.
- Leeks that have been planted in a seed bed can be transplanted into the potatoe bed once the potatoes have been dug up in the summer.
Green manures are an excellent way of planting a crop purely to benefit the soil. They add nutrients that might be deficient, help weed suppression and break up the soil especially heavy clay ones or add organic matter to light sandy soils and thereby helping to make the soil more moisture retentive.