The leaves of the alliums die back as the flower comes out, so it is nothing to worry about. When they go brown, you could cut them off. Or set the pot among other plants so that you don't notice the leaves.

The leaves have done their job, so you may remove them now. If you look at the displays in garden shows they have taken all the leaves of these types of Alliums.
For my rarer types which go into shows I trim the sere ends of the leaves into the approximate shape of the leave as it was before it dried out, but that is just for presentation.

Oh thankyou..Im too hard on myself arn't I ..lol :)

Most people when they first grow Alliums worry about the leaf die back! I certainly did..good to know it means that they are healthy and not failing.

It is kildermorie..us gardeners like to blame ourselves for something we have done wrong and it's not always the case is it :)

I grew 4 of these this year and I have cut the leaves right off today as they were so ugly.