Hi OH
Thank you.
Here in Berkhamsted the geology is chalk and clay so I think lime (or lack of it) is the problem.

Woah, chalk is effectively lime.

Baked and slaked you get lime.

Sorry Peter
I must have blacked out halfway through writing that!
I meant to say that lime is not the problem. I was probably groping for the phrase "I doubt that lime is the problem" and missed!
You are quite right about the calcium carbonate content.

Rotating crops is complicated by the fact that some crops require more land than others and / or we want to grow more of them than the other crops. Potatoes are a case in point, which is why eventually they can make the whole system go awry, no matter how well planned the rotation.
I champion the Joy Larkcom rotation model (it might not have originated with her, but I call it that) which groups plants according to their taxonomy. It is based round the fact that related plants tend to attract the same set of pests and diseases, which is principally what we should be rotating for in order to keep one step ahead of them, especially if they are soil-borne. So, to summarise (and from what I can remember) it groups Brassicas, Umbellifers, Legumes and then Solanaceae in a four-year cycle. Other plant families — well, it does not really matter so much about them, and it embraces the Victorian practise of growing onions in the same place every year. Only when white root rot (which can persist for decades, so cannot be practically be avoided by most rotation systems) shows itself are onions then moved to another spot.
I might have mis-remembered most of this but it does demonstrate, in its principle, a lot that is sensible, in my view.

Just to add tuppence'th about liming: it is always good idea to test the pH of the soil before reaching for the lime bag. Lime is very potent and it does not take much to correct a very acidic soil. There is a risk that repeated applications can make a soil go the other way to become too alkaline.

Far too complicated ..many crops follow each other naturally , we worry too much about rotation .My allotment is a place of stressless pleasure, you sow, grow it then eat it...and enjoy it
If I followed this plan it would too much like a day job !!!
Many crops , runner beans etc , can be kept on the same area, many people have permanant structures for support and just redo the trench..no problem and stunning beans as well !!!
The person next to me has concrete posts and fencing wire and he never moves his beans around the plot..and each years tonnes of runners !!!

I can't see how any crop can follow another one naturally. There is nothing natural about the sowing and planting of crops; it is an entirely contrived process.

I certainly don't lose sleep over it, but I think a certain element of getting away with it has occurred here. I have in the past suffered catastrophic crop failure because of soil-borne pests as a consequence of not knowing what had been grown on the plot previously. I once grew glasshouse tomatoes in the same border for two years running and by the second year they suffered awful verticillium. This is why commercial growers sterilise their soil or don't use soil at all, or alternatively, grow them somewhere else.

Well indeed. I should have mentioned runner beans in the same breath I mentioned about growing onions in the same place each year. You could never do this with potatoes, though, or carrots for that matter, or cabbages, or ...
For sure, we don't need to rotate beans to keep ahead of soil-borne pathogens because they don't suffer from any. But what I think many gardeners miss out on, though, with this practise is the generous gift of nitrogen that the beans leave which leafy crops (Brassicas always come straight to mind here) can really benefit from if they then follow the beans. There's nothing fundamentally wrong with the practise, it's just that, in my view, it seems a bit, I don't know ... mean.

Blimey..far too complicated my freind..and have to disagree ..some crops can naturally follow each other to great benefit, eg my leeks always follow my late potatoes.
Just to confirm I do move my beans around, in fact the tops of this years beans are already in next years trench with chicken maunure , over wintered and mulched with horse manure..ready for next year..
..

Hi Tangoman,
The strength of manure you have for your Beans is far too strong in Nitrogen. You will get beans but you will have far too much foliage.
Better to go light on the Nitrogen and so the flowers when they appear are very visible to pollinators. Too much foliage generally results in a poor set and a reduced crop.
JB.

Can anyone tell me what the time gap should be for tomatoes? I like to grow them in the ground rather than pots/bags where possible. Likewise chillis and aubergines. I need to start thinking about where to put what in the space available next year.

What I like about this http://w.gardenorganic.org.uk/schools_organic_network/leaflets/CropRotation.pdf (it's on the last page) is the winter section.
I'm going to have to sit down and do some more thorough planning.

Hi Stephen,
The information may well be good but why oh why have they made the print so small? I have to increase the print size to such an extent that I loose the structure of the document and then have too much scrolling around and in the end I simply got fed up with it and dismissed it.
Such a shame.
JB.

JB
I do agree and finding your way around the doc on line is more difficult because it is laid out to be printed then folded (I am fairly sure) so that the title page is on the RHS of the back page. I think it is designed to be printed on A3 then folded into an A4 booklet.
Simple chaps like me just have to take it a page at a time!

Hi Stephen, sorry I haven't replied till now - I haven't been accessing the site.

Green manure is ideally dug in before it flowers. What this means in practice is that on a fallow strip you will dig it in in the summer and probably then sow another crop of green manure, which you might need to dig in before the winter. Idealy, the plot is then resown with a third lot of GM, which is dug in in early spring.

I usually get caught out and mine has flowered before I have the time to dig it in. So I have developed the habit of just cutting it down, but it comes up very fast and flowers behind my back!

Hi Mike
Thanks, I did that but think I still got a lot of regrowth, which I am keen to avoid.