Question
We have crown of thorns (5 ft high) in pot. Needs repotting. Can plant live
outdoors in winter In southern Michigan?

Answer
Lois,

Sorry for the delay in getting back to you. No, that plant will not survive in southern Michigan. It plant would not survive a hard freeze here in AZ where I live. Unfortunately, your plant is from a much warmer climate, as are most succulents and cacti. Hope this helps.

http://www.desert-tropicals.com/Plants/Euphorbiaceae/Euphorbia_milii.html

Sincerely,

Greg