In a few articles we have mentioned our plans to incorporate crop rotation on the allotment. Contrary to the comedic mental image of spinning vegetables, this is a very effective way to manage your allotment’s soil preparation and to reduce the risk of crops being thwarted by any soil-bourne nasties that can build up.
For those reading who aren’t exactly sure of how this works: let us run over the basics. All plants can be split into groups based on their botanical features and ideal growing conditions. If we dedicate one area to a specific group or a couple of groups with the same requirements then we can tailor the soil preparation over the winter. For example: brassicas need lots of nitrogen and a high ph (low acidity). So for the bed that we will plant brassicas in we can add more manure as well as some potash or horticultural lime to create better growing conditions for that plant, thus increasing our yield.
There are also certain pests and diseases (p&d’s) that affect certain groups of plants. The longer you grow the same crops in an area the more these p&d’s can build up in the soil. If you only plant a crop in an area for one year in every three, by the time you plant that crop in the same place again any of the p&d’s that developed in the soil will have virtually disappeared.
There are 5 main groups of crops that need to be rotated:
- Brassicas (Brussel sprouts, cabbage, cauliflower, kale, radishes, swedes etc)
- Legumes (peas, broad, climbing and French beans)
- Root vegetables (carrots, beet-root etc)
- Onion family (onions, spring onions, leeks etc)
- Potato family (potato and tomato)
Finally there’s a small number of crops that do not need to be rotated including: lettuce, courgettes, marrows, and pumpkins. We can plant these in any spare soil, so we will try and keep areas of our beds free for them. Other longer life crops such as rhubarb and fruit bushes will be planted in a completely separate part of our plot.
Three year rotation
We are going for the traditional three year crop rotation system as we will have three long beds on our plot. Starting next year our beds will be planted as follows:
Bed one: Potatoes
Bed two: Legumes, onions & root vegetables
Bed three: Brassicas
Bed one: Legumes, onions & root vegetables
Bed two: Brassicas
Bed three: Potatoes
Bed one: Brassicas
Bed two: Potatoes
Bed three: Legumes, onions & root vegetables
There’s out planting plan for the next few seasons people, hope this was useful!