They are predicting 20 below in the next couple days ,
Is there anything I can or should be doing for my semps?
This is much colder than normal for here .
There will be a 6 inch snow covering for the in ground plants , and I can take the smaller pots inside an unheated greenhouse and keep it some what warmer .

My problem... some large unmovable pots and a chicken feeder.

Any suggestions ?

Cinda

Hi Cinda,
I'm no help, never been in those kind of temps but lets see what @valleylynn or @goldfinch4 will say. I'm no expert but think I would rap a big blanket around the pots.

We're expecting the same temps here. As long as your plants have snow cover they should be fine. If they don't, I'd just go out and throw some snow on them. Yes, it would probably be good for the smaller pots to be moved into the unheated greenhouse.

I just got home. Wow Cinda, like Chris you are getting some world class cold going on.
I think Chris's advice is sound, and I also would bring the smaller containers into the unheated greenhouse. The larger ones that you can't move, maybe you could wrap old blankets around and over them? Just until the weather warms up into more normal temps.

Let us know how things go.

Thanks
I will do and it might be till spring before I know who survives this extreme cold.

Cinda

I agree with Chris. I haven't had -20 yet, but did have below -10 a couple of years back. No problem with the semps that had snow cover. I would cover the blankets (if you use them) with a tight weave-count sheet, to cut down on wind penetration. Plastic is a bad idea, do not use it, as it will cause solar heating, which is undesirable with cold nighttime temps. You could also put a few jugs of cold water under any wraps. The cold water will moderate temps a bit by slowly giving off heat during the night and absorbing heat during the days.

Your sempervivums should be just fine. They're easily grown through zone 2, requiring only decent drainage - like the majority of alpines, they are very hardy.

Edit: Perhaps I shouldn't assume.... Grown in the ground or in adequate outdoor containers, they should be completely hardy... but not knowing your particular situation...
Are these reasonably large heavy-walled containers with a good soil volume (> a gallon)? Have you been growing these containers outdoors successfully through past winters? If so, then I wouldn't worry.