Thanks for the replies so far everyone, very interesting.

Here's a local example. A farmer not far from me has had his beets grow into 17-20 KG specimens! He doesn't know why.

We've been getting VERY large parsnips, carrots, courgettes/zucchini and leeks amongst other things, but mostly root vegetables.

Another farmer down from us whose grown carrots for years sudddenly has a field of GIANT carrots - 2 to 3 times the size they would normally be.

Really strange stuff.