Oliver, we manage to grow corn with no difficulty in our West of Scotland climate. If you get the right variety - shorter season/cooler climate it grows great. We use golden bantam. There is absolutely nothing that tastes as good as freshly cut corn. You litterally need to have your water boiling before you cut the corn to get it at it's best!I thought this when Meadowlark said corn was the most rewarding vegetable. I find it hard to grow, even using special varieties, and not worth the effort when so much better cheap corn is imported from Spain and the south of France
I think it looks amazing - corn, sunflowers and squash together just makes me feel happy. Like something out of the Hobbiton garden in Lord of the Rings!!
But I agree not a cover crop as you do need to protect it from wind etc. But ours does fine in one of our raised beds in a fairly sheltered spot. For cover crop I've had very good results with field beans (and of course clover).