[Leisurely]

I have Japanese winter onions, which I planted last year growing in the area I have set aside for onions garlic and leeks in my crop rotation plan. Am I ok to plant the onions I have grown this year from seed in the same area. Thanks

[gobs]

Others might have different opinion but not in my book, it's like using the area for onions forever, not on.

[Leisurely]

It’s just that when I started my allotment rotation plan last year for the first time, I set out five areas, onions etc, potatoes, legumes, brassicas and roots. I put my winter onions and garlic in and have been planting up this year as per the plan. So really my over wintering onions have span two growing years and I now have no where for this years young onions, if that makes sense ?

[Weessy]

I work on the idea that if you use a 4 or 5 year rotation there shouldnt be too much harm in growing onions in one area for both overwintering and maincrop, I understand there are some quite long lasting disease you can get   that can prevent you from growing onions for years but are they easy to catch? or common? what are others opinions?

[richyrich7]

It's not best practice to grow the same crop in the same bit of ground year in year out, but I reckon on newish plots you can as long as you get into a routine after the first couple of years you should be ok.
Don't forget crop rotation is not just about pest and diseases but also about what nutrients plant groups use or leave behind, following onions with onions is bound to lead to a deficiency in phosphate's etc so it would be wise to feed heavily between crops.