Our Deluxe New Coldframe

In late summer I built a coldframe onto the bottom of the Ark.  It's 10 feet long and 2 feet wide, filled with a concoction consisting of commercial "garden soil," "peat humus," cow manure, and real dirt.  I mixed multiple loads of this mixture in a wheelbarrow, and shoveled it into the coldframe by hand.  There's nothing like a little exercise to get the heart pumping.

The long wall faces southeast, and is covered with a double layer of translucent "Crystalite" fiberglass to let in the sun.  The bottom is covered with 1/2" "barn siding," and filled with fiberglass insulation to keep the dirt as warm as possible at night.  The inside of the "dirt basin" is lined with Crystalite fiberglass sealed with silicone caulk, which will presumably keep moisture out of the wooden coldframe structure.

On the right side of the picture is "Laura's ladder" leading to the deck.  We'll be up there by the end of this post.  But first, let's stroll over to the steps for another angle on the coldframe:

This is the view from the steps.  The near wall gets a lot of afternoon sun, so I sheathed it with fibeglass to let in the light.  The far wall is aimed northeast and gets no winter sun, so I sheathed it with barn siding and filled
the space between the 2x4s with fiberglass insulation.

Looking down from the deck.  From top:  potato, mizuna, kale, collards, mustard.  These were planted several weeks later than my coldframes out in the garden, so they have some catching up to do.  Some time before heavy frost I'll be adding an insulated, hinged lid to keep out the cold night air.  It should take but a few seconds to open it in the morning and close it in the evening. 

Hopefully the concept of year-round gardening will catch on, especially in our climate.  The main principle is to protect the plants from heavy frost at night.  This can be elegantly elaborate, as I have done here, or as simple as throwing a blanket over your plants at night.  Either way, winter is prime time for growing greens and root vegetables of all kinds.