Author Topic: Overwintering cold frame management  (Read 78 times)

Halifax

  • Poster
  • *
  • Posts: 1
  • USDA Zone: 5a
Overwintering cold frame management
« on: December 27, 2018, 07:41 PM »
Hi Friends,

I am running a pair of cold frames for my miniature and bonsai conifers here in Zone 5a. I have about 5" of cedar mulch as a base and have mounded it around the pots. Temperature profile in the frames is excellent and it provides 10degF or more of protection at night. My concern is the humidity in the frames ... it's pretty much 90% - 100% at all times and I am worried about molds, etc.

Should I be opening the frame covers on warmer days, say when it is above freezing?

Any other advice on running conifer cold frames over the winter? My web searches have not been productive.

Thanks!
Harry
 

Leo in NE Illinois

  • Sr. Forum Member
  • ****
  • Posts: 305
  • Thanked: 9 times
Re: Overwintering cold frame management
« Reply #1 on: January 07, 2019, 03:50 PM »
Yes, open the cover a bit on warmer days, leave open if nights are mild, above 25 F.

You might try adding an inexpensive 7 inch or 9 inch diameter fan. Point it toward one of the walls, so it moves air around but does not blow directly on the trees. Even a little 3 inch electronics cooling fan could work. You want air moving just enough that if leaves were thin grass, they would be constantly waving in the gentle breeze a litte. You don't need trees swaying, or flapping in the breeze. Leave fan on 24 hrs / 7 days a week.