broad beans that refuse to produce beans

beautiful plants lovely flowers but nooooooo beans. Any idea why?

 

I had this problem last year. GC advice was- have patience! They were right.

 

I have and they are now coming along

 

Once they start to form pinch the tops out, it encourages the plants to put their energy into the beans and also helps keep down blackfly which like the new growth at the tip.

 

Further to Pete's comment - I have a vague recollection that you can eat the pinched out top but can't remember if they're better in a salad or cooked. Or I may be imagining it all... (does anyone know if they're halucinogenic?)