there's a thief at our allotments and someone's had their complete crop of onions nicked - someone else their potatoes. I have a truly beautiful crop of onions the best I've ever grown - now I wish they were rubbish as I fear for their future- all the tops are still green- should I harvest or leave their fate in the hands of destiny? I've heard that if you harvest them when the tops are green they won't store as well?