Coldframes are a really simple and effect way to use the sun and grow abundance. Almost as soon as I arrived to the village I saw the need for at least one coldframe and set about designing and building it.
Basically it is a hole in the ground filled with carbon and nitrogen (compost) and covered with a transparent material (glass/plastic)..
This will work almost anywhere but with a bit of thought and design one can extend the growing season by many months. Digging into the ground takes advantage of the earths stable temperature. As the compost gets processed it gives off a substantial amount of heat to the soil, and the transparent covering allows the plants light and keeps the plants nice and warm. By opening and closing the lid you can easily regulate the temperature on hot days.
I'm not actually sure if this can really be called a 'cold'frame as we are trying to keep it warm but that is how I've heard it called . Anyway, Its a basic method of passive (solar) heating that we should be using a lot more to grow an abundance and variety of crops. Now we mainly use ours for seeding onions in the spring and lettuce in autumn, though we have started perennial onions,sunflowers, pumpkins, courgettes and a lot more. The plants love it, shooting up when everywhere else is frost and often touching the glass and filling the space before it is time to transplant them.
When choosing the location for this coldframe we had to factor in orientation and slope to collect as much sun as possible, distance to gardens for transplanting and we wanted it to be close by and on a route we often use so we could not forget to water it or open it on the warm sunny days.
So, we dug a hole.
Not the first and definitely not the last, we are forever finding reasons to dig.
The hole, aswell as the very first greenhouse and coldframe, and in the background the main communal workshop.
We have a lot of old windows stored so I found 4 that could be attached together to make one for each side and then from recycled door posts we built a frame to hold them at the right angle.
Below ground the frame was surrounded with porous cal stones, called 'tosca' here, which is great at insulating, and above ground with normal stones to absorb the suns heat.
The stone work almost complete.
We filled the bottom with smaller heat retaining stones and built two towers in the center of each side to fill with soil and allow the worms to migrate to the compost layer.
Starting with a thick layer of leaves we piled on the compost ingredients.
Not sure why we have never taken a photo of the fun compost step but it envolves as much tasty mixed fresh manure and straw as we could dump in the hole and still level off with space enough for the top ~7cm of quality finished compost and potting soil.
The windows attached, the stone work finished and all the wood drenched in recycled oil, it was then ready for growing abundance.
So that's how we built a coldframe five long years ago, when we were just starting the adventure of living here. Since then it has served us very well, helping us produce enough food to now be ~95% vegetable self-sufficient. Unfortunately, over the years, some of the glass has broken and been quickly replaced with plastic. Before too long we will replace the windows and oil everything again in preparation for the next season.
We could have put our time and energy into already building another larger greenhouse, but at the time we opted to go for this smaller simpler structure, that still has lots of planting space, so we would have something ready for the following season. Another option was designing an active heating system like a rocket stove mass heater, but we thought it an unnecessary use of the wood and time to maintain a fire and heat all winter long. We have since built a larger greenhouse connected to a living space and we will soon build a rocket stove there. A post will be made when that happens ;)
How much food are you going to grow this year?
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More to come on our life here in an officially abandoned Spanish village, all the permaculture solutions we come up with, and how we practise eco-anarchy in the face of dumb bureaucracy.
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All criticism welcome. I would like to improve my informative writing as I have much to say!
Love the repurposed window ideas for cold frames. I built one for my aunt who lives in a much colder climate than my own, then became addicted to them. I ended up putting together a huge list of plans, hopefully it's helpful to you: https://www.epicgardening.com/cold-frame-plans/
~ Kevin
We are very lucky in the amount of usable materials we have been able to take from the ruins here. And everyone is upgrading windows around here so it is not hard to find single or even double glazed windows in the local containers.
That's really a huge list of designs to get inspired to build the next one, though we will be concentrating on the larger rocket stove heated greenhouse for the time being. We need a place that won't freeze even when there are weeks of no sun.
Saludos
I took a look at your web page, epic gardening. Love the ideas for your cold frames. Looks like you had fun putting them together also. I'll be following you around, if you don't mind. always looking for easy ideas. :) Thanks
I don't know if "fun" was the right word, but it definitely was a challenge? Haha, putting those types of lists together always takes a bit of time. Appreciate the kind words!
This is amazing!! I am very inspired by this smart, yet simple design! I like that you take advantage of the earth's heat and solar mass. I am looking forward to your greenhouse and other future posts :)
Indeed it doesn't have to be underground but it definitely helps. We were lucky to have a good slope so we didn't have to dig down as far to take advantage of the heat.
Cheers for the positive feedback!
I've bookmarked this in case I have the opportunity to try your design one day :) Btw did you use mortar for the stones or just stack them together? I am curious as I have never worked with stones like this before.
:) this was just with the mud that came out the hole as no extra strength needed.
Another post could be on how the traditional walls are made here with cal/ lime.. we rarely use cement except where it can really benefit the design, and lasting durability of construction.
Amazing! Even more inspiring to just use mud!! I must try this someday. Yes, I would love to read a post about the traditional walls building... if you ever have the inclination :)
Very good post. Enjoyed reading everything. This is the first Year I have really noticed People using cold frames. Yours is the best design I have seen yet. 🐓🐓
Cheers, glad you like it. With have a lot of designs like this, as in, not more then a scribble and an idea to start with and lots of puzzling of what we have recycled to fit that general design..
Hi @cardoprimo. I really like this post. And your cold frame seems to be one of the most professional ones I have ever seen. Evnen looks mor like a micro Chinese Solar Greenhouse. Well played and can't wait to read more about your Permaculture journey in clod Pyrenee Spain.
Happy you like it !
I like the design of those greenhouses too,we were thinking about a similar design from the terrace wall but changed because we don't have a direct south facing slope and we have to deal with some periods of heavy snow.
Hopefully see you around here too,
Salud
Doing the best with what you have available is something to strive for actually. So much can be done when you have a creative mind like you obviously do. I personally like the smaller beds. Baring another invasion of grasshoppers this year, I hope to grow at least 75% of our food. I have plans to incorporate a blue berry patch this spring. Sounds like an amazing place to live and I'm looking forward to seeing more from you. :)
Hope you can reach your goal. I think there's nothing more satisfying then a meal that was (almost all) alive less then 30mins before.
Would love blueberries here too, maybe a few this spring if we can find them. We have a couple of nice current, strawberries and allium polyculture nulcei that produce well and we can expand from.
Be seeing you!
I have been wavering between cold frames and hoop houses and @sagescrub sent me this link.
These are great!
I want to lengthen my harvesting and growing season and your construction here is perfect!
As you see in the link from halcyondaze there's loads of options. I've never really been a fan of hoop houses. Maybe further south but here there is too much north wall exposed and no mass for heat storage. Let us know what you decide.
awesome post, keep on going, and i miss you dude. Hope to be back there soon.
Much love amigo!