Allotment Growing

The Three Part Crop Rotation

This is the crop rotation favoured by many gardeners because of its simplicity. After taking out the permanent beds, the growing space is divided into three and handled as below.

The problem with this crop rotation system is that it assumes you will be growing a lot of potatoes and brassicas. The third of the plot left over has to cope with everything from onions and garlic to sweetcorn and squashes.

Neither does it allow much time before the potatoes are back in the same bed and the lime left over from the brassicas is still keeping the pH level high for them. Having said that, it is very easy to manage and any spaces on the plot if you grow too few brassicas for example can be filled with crops from the 'everything else' group.

We'll start our rotation year in the preceding winter - just to add to the confusion. Don't worry, all will become clear.

• Plot 1 has manure added to it and this will feed the potatoes that follow on. The nitrogen in the manure tends to make the soil more acid, which is fine for potatoes that like a slightly acid soil.
• Plot 2 has lime added to take the pH level up towards neutral (7) for the lime loving brassica family in the following year.
• Plot 3 is ignored, although a mulch with compost if available would be useful.

On heavy clay soils you will probably be digging over each winter to allow the frost's freezing and thawing action to break up the soil. With other soils it would be a good idea to sow an over-wintering green manure crop to hold nutrients that would be washed away in the rain.

The green manure can be dug into the soil in the spring to release those nutrients and improve the soil's humus level with the organic matter. On really light soils a green manure is vital to build good condition and adding the manure or the lime in early spring after digging in the green manure is suggested.

The early potatoes that come out of the ground in June and July can be followed with French beans who are not too fussy about the acidity level of the soil and will produce a crop on the same ground.

A lot will depend on your actual requirements when you set up and use a rotation plan. The important part of your crop rotation is to keep things apart for as long as possible. Keeping a plan of your plot and marking in what has been planted where will prove of great value over the years because you are unlikely to remember what was planted where after two years

More on Crop Rotation

• Crop Rotation
• Plant Families & Groups
• Three Part Crop Rotation
• Four Year Crop Rotation
• Five Year Crop Rotation