I have Lewisia cotyledon Elise since two years: I already posted a pic of them in GardenWeb (july 2013). For the first winter I transplanted them from the pots to the garden in october and many survived the winter, but I had to clean the collar of many of them in may 2014 and I put them back in the pots. They were again very beautiful last summer. Last fall, I left them outside in the pots close to the house (to avoid soil humidity).

Question 1 - Was it a good idea to leave them in the pots for the winter? It was very cold last week (-25C or -13F), will they survive? Does the cold temperature affect more a plant if you leave it in the pot?

Question 2 - Are Lewisa cotyledon long lived perennials or short lived perennials?