I recently read something that was news to me: Onions and Potatoes should not be stored together. Something about one making the other "go bad" more quickly than if they were stored separately. So, how close is too close? I typically store onions in a flat cardboard box...like the top off of a case of paper. Potatoes get the same treatment. Then the flats get stored on the concrete floor in the utility room in the basement, generally sitting side by side. Is this too close? I have been disappointed that my onions don't hold as long as I would like. They tend to attempt to sprout and spoil before I have exhausted the supply.