Crops Need Rotating Say The Gardening Experts. But Is Crop Rotation Necessary? In Farming Crop Rotation Goes Back Centuries But Conditions Were Different Then. Here’s My Experience Of Rotating Garden Crops.
I think people don’t always understand what rotation means and that they also confuse agricultural rotations with gardening rotations. So does Crop Rotation in the garden make sense? Do we need to rotate crops every year or can we grow the same crops in the same soil year after year?
What Is Crop Rotation?
Part of the confusion about crop rotations is the definition. To me it has TWO meanings. It’s both about the annual rotation of crops in a given year and the rotation between or over the years.
Let me explain a bit more. In any one year, as a commercial grower, I’d grow more than one crop on a given area of land. I might start with planting lettuce in March, harvest them in June and immediately plant leeks. That way I had a lettuce and leek rotation within the same year.
Next year I might do exactly the same thing and arguably that means I’ve grown lettuce on the same land two years in a row .. ditto, leeks for two years. Many people would therefore argue that I have not rotated my crops properly and am growing the same thing in successive years.
Of course the type of veg I’m growing might vary but the principle will be the same. I’ll be growing the same crop(s) every year. But it really doesn’t matter. If it did then arguably the Amazon and prairies would have died out years ago. And ancient woodland would never exist, because they are growing the same crops for centuries! The are many woods growing just one species, eg oak, beech, Scots pine, etc so the argument sometimes given that woods are a diverse mix of species doesn’t always bear scrutiny.
I used to grow commercial vegetable crops and frequently grew the same crop on the same land year after year. BUT that’s not the same as saying I didn’t rotate. Though I may have grown onions for ten years on the same spot I was also able to grow peas in the same year (rotation) to add back nitrogen.
Farmers often grow one crop a year. For example, maybe they’ll grow cereals year after year in the same fields. That’s then called monoculture and frowned upon by some people.
But, as explained above, in market gardens and gardens we frequently grow more than one crop a year on a single piece of land. Another example would be where I’d grow lettuce followed by a second lettuce crop and then put in peas, all in the same year. Or celery followed by lettuce and then broad beans. Or I’d do lettuce followed by radish followed by leeks or cabbage.
There are loads of variations but each plot grew at least three crops a year. And in many of these variations it meant I grew the same species on the same plot year after.
What this really means is that you can both rotate various crops over the year and still grow the same species on that land at the same time.
In green houses I could get three to five crops a year with no rotation problems. Sometimes that would be five crops of lettuce in a single year. Sometimes it would be several different species in the same year.
Why Is Rotation Recommended?
If we go back to mediaeval times growing was different. Farmers and gardeners didn’t have the understanding we have today. If they grew the same crops in a field for years they eventually had pest or disease problems and the crops failed. And if they kept growing crops without adding nutrients back into the soil then the soil became depleted and crops didn’t prosper. Today we know that if we remove organic matter in the form of fruit and veg we need to replace it with compost or fertilisers. So we no longer have depleted soils.
In the past rotations made sense. And when “Turnip” Townsend adopted the Norfolk Four Course Rotation, on his lands at Raynham in Norfolk, it made sense to grow a rotation of turnips, barley, clover, and wheat crops. This was for agriculture but somehow we seem to have transferred the concept to gardening where it doesn’t quite fit the circumstances.
Are There Now Reasons To Rotate?
Yes. But the only time I’d suggest you purposely do so is when there’s been a bad disease or pest problem that will carry over from crop to crop. That’s actually quite rare. Otherwise there is no reason to do so.
Charles Dowding has been trialing the same crops, eg potatoes, on the same beds for years. He records no adverse issues.
Related Posts:
8 thoughts on “The Crop Rotation Gardening Myth”
Leave a Reply
This site uses Akismet to reduce spam. Learn how your comment data is processed.
“But, that aside, I’d agree that the soil biome reflects what is grown. What we don’t yet know is if that matters in the sense that we can’t describe the ideal biome. Probably the more diverse the better.”
There you have it Stefan
We are still at the beginners level in understanding helpful and unhelpful bacteria but seem to be moving towards using compost,” the more diverse the better.”
I use a three year rotation potatoes peas then brassicas but use crop succession as appropriate.
I am half and half no dig.
In Charles Dowding ‘s published research No all crops did better with no dig.
Also he had access to a plentiful supply of compost and may I add assistants to help grow things more intensively.
Understanding soil health is an important task for the benefit of us all.
Michae, I agree, there is so much we don’t know. but we are much further ahead than just six months ago and keep learning. I strongly suspect many microorganisms are dormant much of the time and only leap into activity when conditions suit them. So we are rarely short of any of them, we are just waiting for them to reappear.
Confess Im a bit of a traditionalist! Several points: While it may not be strictly necessary rotation can bring benefit so to refer to it as a myth might be stretching a point. Different crops require different nutrients and in a traditional cultivated setting require different cultivation techniques so ringing the changes can help balance out those differences. Same cropping potentially changes the soil biome by supporting some organisms at expense if others ( good and bad!). Growing legimes continiously on the same plot deprives the rest if the garden if the nitrogen fixing benefits they bring. So in my book accept not strictly necessary but still good practice.
If we are being traditional we have to consider what traditional really means. What baseline do we use. Arguably traditionally we didn’t rotate, that only came in during the 1700s. Prior to that there wasn’t formal rotations, though some rotation might have happened. It just wasn’t a thing that people discussed. There’s no evidence of it I know from the normal sources.
But, that aside, I’d agree that the soil biome reflects what is grown. What we don’t yet know is if that matters in the sense that we can’t describe the ideal biome. Probably the more diverse the better.
Regarding legumes, in gardening we can move them around the garden but that doesn’t make it a true rotation which is really an agricultural system. But whilst moving them we can still grow the same crops at other times of year. Eg we might start with early pots every year but follow it with different second crops in successive years. This could be say, carrots in year one, legumes in year two etc. In this case are we rotating or growing potatoes every year?
You’re clearly rotating, Stefan. I appreciate that some people get confused by the difference between a sub-annual rotation and a yearly rotation as was carried out by pre-industrial farmers (see below), but rotation is rotation whether it’s on a yearly basis or after each crop.
Rotation very much predates the 1700s – https://www.jstor.org/stable/3741455 – moreover, Mediaeval and Roman farmers were all small scale by our standards, and very much did add organic matter. So it wasn’t simply about having to rotate because of a limited understanding of the soil, but almost the opposite.
I do however appreciate the point that you make that the sheer volume of organic matter added in a no-dig system probably precludes the need to rotate unless there are pests and diseases. But equally (and especially for most of us who are only partially no-dig, or not at all) rotation seems to have a lot of potential benefits for very little mental effort. For example, I know I have allium leaf miner on my allotment site. Rotating everything saves having to think about whether the particular bed I’m putting my onions in had alliums last year, etc etc. I’m with Matthew – perhaps I don’t need to, but it saves mental effort and is clearly good practice (and something that, on a sub-annual scale, you’re doing yourself!).
Yes, I’m growing different crops in succession. But that isn’t the definition of rotating which is an annual process. I often grow the same crops in the same place each year which means I’m not rotating in the annual sense.
Charles Dowding only adds 3cm of organic matter once a year to his beds, with great results and no other fertilizer…
Exactly. He adds a bit more the first year but then it’s only a small amount each year.