Sounds great, but what happens when the sun isn't shining for a couple of days?. Do you have heat? It's zero degrees out right now. My little tent type, with no attempt to insulate, got up to 56 today but is 3.6 right now 8:00 PM.
I quit on it several months ago. I am going for a btter one next year.
KennyP

Dan, that looks very nice. I'm in the middle of building a cold frame from a discarded window frame (6x3 feet). Hopefully I can keep up with the daily maintenance

Kid, I use water to store heat. The big coldframe in the background has walls ~R6-ish*, and only once did it drop below freezing in the prior two years. The backside of the one in the foreground has several layers of insulation, and if you look closely you can see bubble wrap on the side. I don't have to cover unless it drops below ~15F. Did you pick up that HFGH on sale?

GJ, if you go out Chenango to Picadilly there is still new construction going on and they are quite wasteful in their framing material. Lots of chipboard there when they are framing.

Dan

Dan

Is that thing home made out of cattle fence, or did you buy it? Are there some kind of spacers between the layers of plastic sheet? Does the vent open automatically, computer controlled, or do you have to go out and open and close it by hand?

I've got my bamboo all covered up with plastic. It makes kind of a cool little attrium inside there, but I'm certain it gets well below freezing in there some nights.

Bruce

Bruce,

yes, this year's project was the cattle panel frame. I don't recommend it except for strength against snow load. I used cheap furring strip, painted, for purlins. On the inside the (2) purlins (1) hold up the inner layer of film & 2nd creates an air gap. On the outside they secure the outer layer to the inner purlins and keep the film from flapping in the wind.

That is an auto vent opener, a cheap one from Harbor Freight that seems to be doing a good job so far. Next year I will build a structure similar to this, but use a PVC frame and secure film by ripping a pipe in half and screwing the sanded sections to the frame. I'll make a bigger vent as well - got up to 87F in there today despite the opening being 17.5% of the area of the ridge...I have ~ 4 gal of water inside in black containers to retain heat at night. The film is excellent and very reasonably priced from Farmtek.

Dan

Bumping to reiterate:

Last night it was -8F at the house. The new hoop above was covered for two days, it got below freezing for less than an hour. Right now it is 16F outside, with full sun blasting down at 698 W/m2, and inside it is 76F. Couple droopy leaves on lettuce are only damage. Other hoop with cabbage/spinach looks like it came thru OK as well.

Dan

My cold frame is heating up nicely today too. It was up to 70 F this afternoon. Which seems pretty warm considering it's not into the ground yet.

Dan,
I really like your set up. I didn't realize how high that bed is raised. I didn't catch that in your earlier photos. I bet that cattle panel was a bear to bend! The temps you're getting in there are amazing. I'm looking forward to seeing your new PVC frame this year.
gjcore, sounds like you'll be on your way soon!

I have a friend with a similar setup, Dan, and at some point he swaps out the plastic for mesh to keep bugs out. I'm impressed.

Thanks folks.

The parcel is sloped from front to back, and the start of the wall at front it is 14 inches high and its terminus is 32 inches. It was fun to make. I hadn't thought of the mesh idea. I'll have to think that through. I really like that particular greenhouse film and am thinking of more ways to use it, so swapping...hmmm...

:o)

Dan

I put seed into the cold frame today. Spanish Gold Onion, purple plum radish, Red Acre cabbage, red wing lettuce, alaska peas and mesclun mix. As much as the soil has warmed up under the cold frame recently I think these seeds will germinate fairy quick. The experiment continues...

maybe pictures soon

I've got good germination even with the below 0F temps, and looks on track to get everything out by mid-April to replace coldframe with potatoes. Lots of sun pounding down and the cabbage is really moving along now. Fun!

Dan

Quite a few of the things I planted in the cold frame are sprouting. I was hoping to use only passive heating to get through the end of the winter but now I'm thinking I might need to resort to active heating. I have a few gallon jugs filled with water that have a few different food coloring dyes added to the water to make it dark.

Today being cloudy I'm not sure how warm it'll stay overnight. It was 45 F (outside temp was 22F)in the frame this morning but for sure it will be colder overnight. My first thought was to put an electric bulb inside but nixed that fairly quick because that would leave a gap in the top. I guess I can go out and bury the electric cord underneath the frame or maybe add a couple gallons of hot water.

You were on my list to e-mail today and forgot. cover glazing with a sleeping bag and put in a jug with really hot water.

Should be OK, as your soil has heat in it.

Dan

I bought a wireless thermometer today :-) Now I can monitor the cold frame temperature without leaving the office chair :-)

It's not nearly as nice as Master Dan Staley's setup but here's a couple pics of my cold frame

I was thinking of moving the cold frame in a few weeks. The lettuce, peas cabbage, radish, onions, collards and mesclun will have to fend mostly for themselves. The cold frame will then be used for hardening off.

Dan warned me that once I had one cold frame that I would want another. I just finished this one that's going to be used mostly for hardening off.

Greg

Almost a year later and the coldframes/hotbeds are coming along nicely. With the Christmas lights and covering the tops with an older sleeping bag or a space blanket has been keeping the insides of the hotbeds about 50 degrees higher than the outside temperatures.

The Christmas lights add a festive look at night if not covered by blankets.

Greg

Greg,
Functional and festive! I think I'll have the better half help me build one in the spring. You and Dan have made me a believer. How nice to have greens growing in this cold!
Good job!

Barb