What's wrong with my Alliums?

If they are the tall ornamental Alliums then that is the way the foliage goes. It usually has disappeared altogether by the time they get to flowering.

Thanks a lot, Owd'un!

could be frost damage too. some of mine have done this, this year and i assume it is frost damage.

The secret is to have something planted in front so it hides the dying foilage.

Thanks to you all