I planted asiatic lilies in a pot with ornamental grass in the middle. How do I keep this over winter?

I've been thinking of keeping it potted in my greenhouse which will be cold and not in use over winter. Is this alright or do the bulbs need to be removed and stored in a dry place?

I can't see why not! - as long as it's warmer in there, like you said it would be...
Good luck!

My greenhouse will be cold during the winter, but it will be closed up.

I also have a rose bush in a pot, will this one be alright here too?

Rosepetal,
I've had some lilies in little 4" pots and they over wintered..
I did keep some shredded leaves around them..
but I think it was a mistake cause the moles liked that idea tooooooo much and ate some..
but the one's not eaten survived quite nicely..
Lilies do need a cold period, and I would only worry about the sunny days towards the spring time days...
If it starts heating up early, inside, they may sprout too early...
That would be my only negative thought on it...

Good idea Weezie, thanks for the info'. I think I'll be ok in the greenhouse with my pots. I'm going to do it this way and see what happens next year.