We built 2 cold frames last year. One was about 7' x 3 1/2' and was sized to fit a storm door we aquired. The other was about 8' x 4' and we topped that one with plastic (it was stapled to a wood frame that could be moved to allow air flow). The big one worked better, but I think that is because it was in a spot that got more sun. For the fall/winter, the following crops did great: arugula, baby pac choi, radiccio, endive. In the early spring we were harvesting spinach I planted in september, and that was the best spinach crop I have ever gotten. In early spring we planted lettuces, more arugula, mache, and some other greens that did well. All in all a great experiment, that will be continued this winter!

Our biggest problem is keeping the chickens out of them when we open them up to vent.

Irene

PS - I also used hay bales to help insulate the one cold frame - we had a brutal winter.

I used hay bales and old storm windows last year and it worked well. Of course we had one of the warmest winters on record but the temps did get down into the low 20's a couple of times My lettuces froze solid but were just fine.

I'm looking into something more permanent to build this fall.

Hi everyone,aka_Peggy did you use plastic over the hay?Im thinking about useing small bales of straw and covering the straw with plastic and makeing frames for the tops out of 2x2 or 2x4 s and wrap them in plastic , i plan on trying this for a cold frame and a second one with a fresh hot compost pile made of kitchen scraps and chicken manure and pine shaveings to help take the chill out of it although i might have to wait for it to cool off a bit befor i plant because the chicken manure stays hot for a long time.And then i plan to use the same straw for multch in the spring. MIke

I too use shower doors. They give good light, are safety glass, and cover a lot of area. I build frames that allow me to counter-weight so that they aren't so heavy to lift. That way I can install the automatic vent mechanism so I don't have to monitor it all day. I like the idea of using hay-bales for insulation, but I would wrap them in black plastic to repel water and absorb heat

Mike,I seem to remember reading somewhere that I believe the pioneers used to dig a hole for a type of cold(hot)frame.In the bottom they would layer their fresh compost materials such as kitchen scraps etc.Then maybe dirt over this and plant over this.As the compost materials cooked it provided heat in the frame to keep things from freezing.I would live to find more info on this again.hope thgis gives you something to think about.
Tammy

Hi, i havent started anything yet but a neibor gave me two doors i think they are 8' tall by 5' or 6' wide with very thick glass im trying to decide how to use them and i still plan to use the straw just been real busy with all the new animals pigs, goats and rabbits ,thanks for the info tammyinwv thats kinda like what i had in mind i will have to get a book i think so i dont cook everything heh : ) . Mike

Tammy,

I don't think it was compost at the bottom. A traditional method is to fill the bottom with fresh manure. That's the source of heat.

Seed flats and boxes of seedlings are then set on top of the manure, so they aren't making direct contact.

My DH built a cold frame for me a couple of years ago. We use it to start seedlings and harden off anything that I've started in the house.

It's made of 12" boards with two old windows on top. And frankly, its too heavy to move. I did have an "automatic" opener on it, Loved that gadget!!! But the windows are too heavy. I need something lighter to really make it work well.

Also, when you use compost or horse manure to warm it up, I think the name changes to "hot bed." My Grandfather had 2 big beds, dug in, by the side of a building, they were made of cement blocks with glass covers. He would get a load of horse manure from the barn, load up the hot beds, and they would STAY hot all winter.

This was back in the 60's, and he said his father had done it that way. I don't recall what he grew, but they always had fresh vegetables, they didn't eat much meat.

I've been trying to design a cold frame, too. On the web IÂve mostly found prefabs for sale, so far, but will dig deeper soon. Some of the ideas IÂve had are:
Make the roof A-frame, back (north) slope being a sheet of foil-coated foam insulation (Thermax?). Light could reflect down to the plants.
Put the lifter on this lightweight side.
Net the inside of the back so bugs donÂt come in. Plants will be accessed from the front side, so the net shouldnÂt be in the way.
If not using the hot-bed manure trick, line the lower back wall (below roof angles) with dark-painted cement slabs, 2Â x 12Â x 12Â size, to provide thermal mass.
If the lifter is to be mounted on the heavier side, perhaps have the window open at the top where much less force will be required. Problem with this idea is that the window would then open down and be in the way for plant access.

I have used coldframes made out of plywoos topped by glass (old entrance storm door inserts) hinged to the box. There are two very good articles you can probably find in your library which give excellent pictured instructions on how to build these reusable gems. One is in the November/December of 2003 Organic Gardening Magizine which is very sophisticated, and there is a more plain one in Horticulture Magazine of December of 2003. Check also your local couty extension service for plans for a cold frame. In the past I used my coldframes for over-wintering plants and hardening off seedlings of vegetable and flower plants which I grew inside but this year I made two more frames to extend the cool weather vegetables in my vegetable garden and so far it is working great.
Good luck,John

P.S Make sure you start with a window and size the frame around the size of the window. duahhh!

John

Thanks for the ideas on the cold frame. I've been toying with a small greenhouse and this post fits right in with my size requirements.

Your ideas for storm doors/windows reminded me of a sliding glass door I've been saving. I changed my plans for it and will add double French doors instead and now can use this for more than smashing the glass, and scrapping the aluminium frame.

I'll build a frame for it and use my other idea of clear, corregated plastic sheets for the surround (sides and top). I'll get a 'room' of about 8' across by 6' tall, by 3-4' deep and a sliding glass door. I'll back it up against my stucco house for thermal mass.

My previous plans called for a PVC pipe frame with clear corregated plastic sheets for the 'walls', 'roof', and door'.This setup would be more portable than a sliding glass door set in 2x4's however.

i am also about to start constructing a series of frames on my allotment. I will be using breeze blocks for the sides with the back higher than the front. I am going to line them with polystyrene which you buy in slabs for roof insulation. The polystyrene will be 50mm thick. The important thing is that the lining will be flush to the breeze blocks but level all round, therefore the breeze blocks will be approx 30cm higher at the back than the inner lining. For glazing, i am having it double glazed - the outer layer placed on the breeze blocks, obviously sloping downwards. the inner glazing will sit on the polystyrene. When condensation occurs, it will fall evenly off the inner glazing rather than pouring to the front of the frame and down the wall. The double layers of concrete and polystyrene will provide very good insulation as i am planning on using these frames to start lots of veggies and flowers without any extra source of heat.
I know this sounds complicated but it is not and it is also fairly cheap to build. especially if you can use salvaged windows. Breeze blocks and polystyrene are not expensive and do not need to be cemented in place (altho' i may as i am planning on building four, 2.5m x 1.2m x .5m-.8m high, in a permanent spot). I may also build one which is 1.2m square and use it as a hotbed - useful to grow melons in East Anglia (UK).
Have fun

I built a cold frame this fall out of scraps found on the site of this house I'm renting. Starting point was 2 storm windows each about 42" x 30". The sides are partly 2" thick wood (the good bits salvvaged from some old raised beds I ripped apart) and partly 2 thicknesses of salvaged wood siding. It's set on top of the gravelly area on the south side of the house with a white wall behind it for reflection, and filled with about 12" of good soil and compost.

I finished it at the beginning of October and planted radishes, mustard greens, lettuce, spinach and green onions. According to the books that is too late for all of those here but so far the mustard greens are doing very well and are worth harvesting outer leaves off every few weeks, the lettuces are about 3" across and still slowly growing, the radishes have roots about 1/2" across, the spinach stopped dead when it got a couple of true leaves, and the onions sprouted then stopped. I assume the onions and spinach will start again when the light levels improve in spring (they are at the front of the frame and partly shaded by the front wall when the sun is this low). We've had colder than usual temps through November which has probably affected things too, but I am pretty pleased. It cost me CN$1.99 for nails :-)

Kevin
Powell River, BC

See pics of mine at:

http://home.comcast.net/~cherie1/Garden/Cold_frame/Cold_frames.htm

or click link below.

Thread at:

http://forums.gardenweb.com/forums/load/frugal/msg1123502613030.html?13

Cher

Here is a link that might be useful: Pics of cold frame (gone hotbed)

A man must always have a pick up truck !!

when I had the Diesel Golf, I had to transport fifty 4" by 8' by 4' pieces of free used white syro-foam - great for projects and insulating projects.. I had to pre-cut, but this was time consuming, and after three days, the huge pile was gone, I only scrounged 20% of it!! Then I used the truck for hauling compost and manure, still ran at nearly 40 mpg..

But I think the straw bales are just as good for the cold frame sides, or doubled hay bales, then the hay can be used in the summer time to cover the potato crop..If one has a south to south-west heated exterior wall, then I think the cold frame would be able to generate all kinds of fresh veggies;;spinach, broccoli, endive, celery?..