I have never tried growing during the winter period, so thought now would be a good time while the squares were starting to clear out.  As well as turnips, I bought some Japanese onion seed and some broad bean seed off Ebay.   At the same time I bought the seed potatoes for the winter harvest.  Winter is going to be quite sparse and so four squares of onions would seem a good idea, esp with the idea of losing some.  Two squares of parsnips and right at the back behind the tomatoes are two squares of broad beans with one square in front of them.  When the carrots are pulled up, one of these squares will be used for broad beans too.