Dennis and others, Polianthes culture has come up on this list before - there is plenty of information out there. Polianthes tuberosa is not reliably hardy here in zone 7 Maryland unless very carefully sited (i.e. next to a sunny wall). But that position is not really a good choice for this plant because it's likely to be in the rain shadow of the house and the tuberose responds very well to copious water. In fact, if you are growing the plant under the sort of conditions which will eventually require that you dig them for the winter for storage indoors, I would suggest that they be grown during the summer outside on a dung heap which is watered frequently. If they are in a pot, place the pot at the edge of a pond or keep it on a saucer of water. When they are in active growth I don't think you can give them too much water, and they definitely respond well to rich conditions. Although it's closely enough related to Agave to hybridize, the sort of growing conditions usually associated with Agave are not really what this plant needs when it is in active growth. Jim McKenney