I actually live in the South of England, so coldish Winters. I only know it is white! It was a gift for me that came from Next for my birthday. So do not know what it is exactly. I do have a greenhouse but it is not heated in Winter. Maybe I will try it outside when all the flowers drop off and if it survives and bring it back in for Winter. So far I have had it a few months and it is doing well, normally they die on me. What I do is let it dry out completely and I can see it is from just seeing it and then give it a soak in a bucket to take in water for 2 or 3 hours and that seems to suit it. Then I feel the compost and it feels very wet but does not stand in any water. If I have water in the butt I use that rather than tap water.