Before we start to talk about our plan up at Muriel Jones for 2021 we wanted to spend some time talking about crop rotation - what it is and why it's important.
Put ever so simply all it means is that we try not to grow the same group of vegetables in the same part of the plot every year. The reason we do that is to prevent the build-up of crop-specific pests and diseases, to allow the soil to recover and best meet the needs of the crops that we sow in it and to give us a helping hand with the inevitable weeds!
Some more detail:
Pests and diseases: Soil pests and diseases normally affect specific plant groups. If the same group of vegetables are grown in the same spot year after year then those pests and diseases will build up. If we rotate the crops then the pests normally reduce in the seasons when their host plants aren't there. This helps reduce the build-up of those spores, eggs and pests.
Soil recovery: Different crops take nutrients from our soil. If we change what crops we grow where every year then this reduces the chance of particular soil deficiencies developing. Crops that are say, nitrogen heavy, will use up the nitrogen in the soil if left in the same bed every year. By rotating them - and perhaps growing something that might replenish the nitrogen over the winter (more on green manures another time) then the vegetables that follow will thank us for it!
Weed control: Crops like potatoes and squashes - those with dense foliage or large leaves - help keep the weeds at bay. As we know everything needs, amongst other things, light to grow. Those large leaves help us by reducing the need to weed and hopefully the number of weeds in future seasons.
We've tried our own crop rotation at our allotment in the past but time has always got the better of us and as we've tried to trial different things - no-dig, different types of vegetable and variety, fertiliser and feeds - we've never really been able to follow it to the T. This year though things are going to be different!
Vegetables fall into different types of group that we'll explain shortly. Some vegetables fall outside of those groups. We have a perennial vegetable at the allotment - rhubarb (yes, rhubarb is a vegetable!) - and that doesn't fit into the rotation. It stays where it puts down it's not inconsiderable roots. Certain other annual crops such as cucurbits - (in our case courgettes, pumpkins and squashes) and French beans are grown wherever we can squeeze them in - but we do try not to grow them in the same space every year.
We'll show you different ways to try certain types of squash and courgette later in the season, along with how we grow some of our lettuce in a variety of containers......
As with everything planning is vital. We know the size of the beds at the allotment and when the time is right - around now - we get all of the seeds we bought at the end of last year and start our plan. This is what it looks like for one of those beds for now. We've got to do some work on the other beds and we'll post all of them together when we've finished that.
How to do it.
Firstly divide your growing area into sections - ideally of equal size or in accordance with what you like to grow - which should ideally be linked to what you or your family and friends like to eat! Add an extra section for perennial crops - we've done that in our marginal space for our rhubarb.
Then we need to group those crops:
Brassicas: Brussels sprouts and several types of kale for us , but can also include cabbage, cauliflower, radish, swede and turnips
Legumes: Peas, broad beans - French and runner beans suffer from fewer soil problems and we grow our climbing Borlotti and French beans wherever we can
Onions: Onions and garlic for us, but can also include leeks and shallots
Potato family: Potatoes for us as we tend to grow tomatoes at home
Roots: Beetroots, parsnips and carrots for us, but can also include celeriac, celery, Florence fennel, parsley, and all other root crops - except swedes and turnips, which are brassicas
There. Vegetable groups. What next?
Well we rotate them! Each vegetable group is rotated to a different part of the plot every year - like this - brassicas follow legumes, onions and roots, legumes, onions and roots follow potatoes and potatoes follow brassicas.
A 3 year crop rotation would look like this:
Year 1 Plot A: Potatoes Plot B: Legumes, onions and roots Plot C: Brassicas
Year 2 Plot A: Legumes, onions and roots Plot B: Brassicas Plot C: Potatoes
Year 3 Plot A: Brassicas Plot B: Potatoes Plot C: Legumes, onions and roots
This year we're trying a 4 year rotation. We're doing that by dividing up parts of the larger beds and growing fewer potatoes and brassicas. We're going to be organised this year and net off those brassicas so the pigeons don't get them. That means we won't need to plant so many - fingers crossed!
We like our broad beans (as did the rabbits last year) so we're growing more legumes - which tend to take up a lot of space. We have plans to try and re-use that area once the harvest is in by planting our kale and although not strictly part of the formal rotation we thought we'd go with it and see how it works. Time will tell! We had some great success with Red Baron onions last year - we still have loads left so we're growing them - and some garlic - this year.
Our 4 year rotation looks a bit like this:
Year 1 - 2021 Plot A: Legumes Plot B: Brassicas Plot C: Potatoes Plot D: Onions and roots
Year 2 - 2022 Plot A: Brassicas Plot B: Potatoes Plot C: Onions and roots Plot D: Legumes
Year 3 - 2023 Plot A: Potatoes Plot B: Onions and roots Plot C: Legumes Plot D: Brassicas
Year 4 - 2024 Plot A: Onions and roots Plot B: Legumes Plot C: Brassicas Plot D: Potatoes
And that, for now, is crop rotation. The weather forecast today is good so we're off to the allotment shortly to check our measurements for the areas where we're planning to grow our International Kidney potatoes, our climbing Borlotti and French beans and a dwarfing variety of Borlotti beans - Tintoretto. When we've done that we'll be back and put the finishing touches to our plan - that we'll then share here.
And when we know how many of those seed potatoes we can get in the ground we'll start chitting them!