Nice work. I starting collecting C & S for the first time last fall. Most of them overwintered very well either in the house or under lights in the garage. I put them outside and all was well until we were unindated with rain last month--4 and 5 storms a day. Most of my semps just rotted, except for a few named ones that I kept inside under lights during that time. Unfortunately I have neither a covered porch nor a greenhouse. Looks like I'll be growing those in chicken grit with a little soil added. I lost a large Cereus Forbesii Cristata. I was late putting it outside and put it under a tree. A couple of days later some parts of it started looking peaked & turning black, so I cut off the bad part and left it in the garage under lights. I thought I'd sunburned it. It seems like one day it was fine and the next thing I know the whole plant turned black and collapsed. Rot, not sunburn.
It's a good thing Lowe's has a 1 year guarantee on their plants.