Topic: rotation question

[Sarah-b]

Have just read thread on onions after pots and am a bit worried. I have got onions in the same rotational group as peas and beans. I'm not sure why - but is it a mistake. Do I need to re-plan the whole one and a half plots?
Sarah

[rdak]

Sarah,

Some rotation plans but these in different groups, but some put them in the same. The simplest established rotation plan is Roots /  Brassicas / Others, in which case you should be OK. Others put Alliums in their own group. In terms of soil, both like rich nitrogen soil and good drainage so I think you'll be OK. Although I'm sure I read somewhere that said onions and beans are not good companions and are antagonistic, but that said, a lot of so called established wisdom on companion planting is often proved wrong and I'm sure lots of people out there are growing onions and beans together without seeing any noticeable adverse effects.
So if I were you, don't worry!

[Hugh_Jones]

While nutritional requirements are undoubtedly a factor in planning crop rotation, the most important reason by far for rotation is the avoidance of disease build up, in other words to make sure that apart from crops like runner beans (which can occupy permanent stations) no crop grows in the same soil more often than once every four years, that you never plant potatoes in soil that has been limed the previous season, and that you never sow carrots or parsnips in recently manured soil.  Once you have worked out the basics for that everything else is merely fine tuning.  There is nothing critical in onions following potatoes, and any minor differences in nutritional requirements can easily be dealt with by using appropriate fertilizers.  Indeed, Lovell Hill (who won more show prizes that most of us have had hot dinners) grew his prize onions and leeks in a permanent bed which was simply refreshed annually with heavy dressings of compost and bone meal.

[Multiveg]

I think RObinsons grow their onions in the same bed (I imagine they heap compost/manure onto the bed)