Adam, Norman, et al. The reason I take my pots of Sprekelia out of the weather during the winter is because of the unremitting rain we get in that season. In the ground, it would be different -- the ground can absorb the water. But, potted plants do not fare so well with the excessive water. I don't actually take these plants in; I keep them outside, under a roof. However, I am aware that Sprekelia formosissima can thrive in this climate when planted outdoors. But, I am astonished that you can leave it outdoors in Chicago. I lived in Chicago for a few yeas; there is nothing mild about Chicago's winters.