Leave them alone until they turn brown in the fall, then snip them off to the ground. They are busy making food for their bulbs right now. You can snip off just the spent flower area right now, if you want.

northspruce....

Would u keep it watered after it is finished blooming and turned brown? Mine is in a lg pot.

I'm not too sure... up north here once the leaves turn brown, the ground freezes soon after! Also I don't have any lilies in pots. But an educated guess would be to keep them just barely moist but don't drown them. Hope that helps.

Since your lilies are in a pot you need to make sure there is proper drainage. There must be some sort of holes in the bottom of the pots for the water to drain to. Lilies are extremely tough plants except if they are water logged for too long. After they turn brown cut off the stems 1" above the soil and leave then alone outside for the winter if you plan on keeping them in the same pot. If you want them in the garden plant them after they turn all brown and die off. Don't bring them inside for the winter. They need to be frozen for the winter same as tulips.