I have a 4 X 4 bed. What is the correct spacing for artichokes?
I have no idea, I hope someone else has tried this.
I hate to admit I've never even eaten an artichoke, let alone grown one. A quick Google search gives ranges from 18" apart up to six feet apart! So the very least you could get by with would be 18", or maybe 9 per bed. It might be safer to put in only four. The link below gives the 18" spacing.
Here is a link that might be useful: Growing Artichokes