I have tulips in pots, whats the best way of overwintering. I have an unheated greenhouse would they be ok if left in that, do I cut the dead stems back to soil level or is it better to let them die back completely and take the stem off then. Also, will I need to water them during winter.
Tulip bulbs in pots will be fine just left outdoors for the winter. If they have been in the pots since last spring, they have probably sprouted roots by now. You can simply pull away the withered stems or leaves and let the tulips come up. It is likely that flowering will be reduced or absent, as the bulbs may not have built up enough bulk to flower the following year. In that case, they can be planted into well-drained soil in an open sunny spot.