What is this?

Hi.

So I planted a container with some bulbs last autumn but after the local cats using it as a toilet I ended up losing the id tags. After covering the pot with netting I managed to keep the cats away. Now I just can't remeber what I planted and these huge (2ft) single stalks have come up with a flower bud that doesnt seem to want to open? Does angone have any idea what they are? 

Many Thanks