The Great Cold Frame Experiment

[JimWWhite]

I've been planning on building a cold frame like you have here using hay bales and a big sliding glass door on top. But there's something I recently heard about and will be trying later in January when I set up my cold frame. What I was reading was that you cut a trench down about 18 inches below the surface and fill it in to about 8 inches from the top with raw horse or cow manure and then cover it up back up to ground level with dirt. Then set your cold frame directly on top of this. It seems the rotting manure will generate a lot of heat for quite some time thus keeping your cold frame warmer. I'm going to give it a try. I'll try to report back and give dates, inside and outside temps throughout the time I'm using it.

 

[wifezilla]

I have read about that, but lacking a cow or a horse and easy access to either. I will have to do without

Took one more reading just for giggles...
Day 3 - 2:00 pm
Temp at ground level: 54 degrees
Air temp outside the cold frame: 61 degrees

Obviously on the upside the temperature is being regulated, but the lows are still too low.

I guess I lied about being patient. I went ahead and added black painted water containers. I will skip measuring tomorrow and give everything a chance to settle. I ended us using 2 vinegar jugs, 2 apple cider jugs, a 5 gallon plastic carboy, and a 6.5 gallon plastic water can similar to this...
http://www.kmart.com/shc/s/p_10151_...003a&ci_src=14110944&ci_sku=1170000002223550P

Of all the things i used the 6.5 gallon container is the best since it is narrow and tall. I wish I had a lot more. I kick myself for not buying more during garage sale season. I saw them everywhere!!!

 

[wifezilla]

I checked the cold frame this morning and the temp was 30 degrees. That doesn't sound like much, but our high yesterday was only 36. Checked it again (4pm) and the temp is now 38 and our high today was 40. Seems to me that the temps are stabilizing and slowly rising. The thermal mass in the water and the hay is acting like a battery and slowly charging. We will see what the temps are tomorrow. I am pretty optimistic that by next week I may be able to start planting

 

[Organics North]

Nice project WZ..

I in my hoop house I have a cold frame of sorts. The center bed is covered by a second hoop. In October I loaded it up with transplants of: Broccoli, Spinach, Chard, Kale and so forth. It is frozen solid these days.. Low sun, dark heavy cloud cover with snow for weeks on end = no solar gain..
I am optimistic that everything should winter over well...

No active growth in my clim...
ON

 

[wifezilla]

Overnight low.... 18
Air temp at 8:00am....23
Temp in the cold frame 8:00am....38





I am planting in the next couple of days

 

[thistlebloom]

Very cool wifezilla! How exciting is that? Your temps made a huge jump didn't they? Probably the black jugs you added to the back wall d'ya think?You've inspired me to get on the stick with some garden experiments that have been knocking around in my head for awhile. Mine will have to wait for spring tho... Keep us posted on your progress!

 

[wifezilla]

I know it was the black jugs. Adding thermal mass does wonders for keeping wild temperature swings at bay. I was just hoping the clear water tubs in the front would be enough. It wasn't, but adding the black painted jugs was an easy fix.

I need to buy an extra hay bale on payday so I can get started on the second cold frame. It will be next to the first so they can share a wall and cut down on materials.

 

[Chickie'sMomaInNH]

have you also thought about using clay bricks at the back wall where the sun may hit them? those should also help retain some heat similar to the water jugs, without the possibility that the jugs/tubs could freeze and crack.

i may just try experimenting with a cold frame this winter too! i loved the carrots i harvested after they got a good dose of frost here!

eta: and don't you have chickens? if you filled a 5 gallon painters bucket with their shavings/straw and manure that may also be a good source of heat to help!

 

[Collector]

I have been watching your progress with this project. I was thinking it wasn't going to pan out for awhile, looks like I am going to be wrong again. I will be watching to see how things are progressing. Good luck it seems to be going well.

 

[wifezilla]

I don't have chickens, but I do have ducks. What I don't have is extra room. If I put anything else in there I wont have room for plants! I was planning on adding some aged duck straw around the plants once the seedlings emerge.

As for the jugs cracking...no biggie. First of all, I left plenty of head space so if some freezing did occur there was expansion room. Second of all, if it does split, I can easily replace the jug and that is one day I don't have to worry about watering

I have also experimented in the past using 2 liter bottles in a ring as a redneck "wall-o-water". I never had them freeze enough to burst. My area of Colorado seldom gets below 0. Our night temps are usually teens and 20's. If I was in Northern Wisconsin, I would probably have to worry a lot more.

If I had expensive containers I didn't want to risk rupturing I could just add some salt to the water. That lowers the freezing point.

Clay bricks could also work. If I had any extra that would have been a potential thermal mass material. All bricks at my house, however, are being used as paving or garden edging. Nothing to spare. 2 liter bottles though...with a soda fiend son living at home I have a steady supply.

I checked the temp really quick around 4pm this afternoon...
Air temp outside... 40
Cold frame temp at ground level...38

Holding steady!

We'll see what the temp is tomorrow AM. I would love for it to break 40 in there, but we are almost to the shortest day of the year. 38 may be as good as it gets. That is still above 32 and planting temps are far as I am concerned