Not Exactly Grandma's Cold Frame
Published: 2017-02-09Tags: парник, удължаване на сезона, бали слама, градина в слама, студена рамка
Translation
This is a translation of a Bulgarian-language post. It conveys the content faithfully but is not the author's original English writing.
In all the yellowed little books — whether for the amateur gardener or the professional vegetable grower — the so-called cold frame is cited as a common method for extending the season. It is a board frame with a transparent — glass or polyethylene — lid, set at an angle, which allows the maximum exposure of the sowing to the already scarce light at the end of the winter season, as well as the maximum retention of the heat accumulated under the frame; and so you secure a harvest 15 to 20 days earlier for some crops that are not so demanding of warmth, such as radishes, spring onion and lettuces.
Everything needed to make our cold frame: straw bales, old newspapers and cardboard. You also need an old window frame in the size you want, and the corresponding amount of soil-compost mix or bio-fertiliser.
Since I have personally tried the method of a garden in straw bales, and intend this year to keep experimenting with straw, I decided that the most natural thing would be for my "cold" frame to be in bales too. Accordingly, we can no longer call it a cold frame, because, as we know, straw is an exceptional insulating material — we have all at least read about whole houses made of straw bales, used precisely for that quality. Besides, I borrow one more old-fashioned method — a heap of heated bio-fuel, in which layers of farmyard manure and straw are arranged, and with favourable moisture (70%) and enough oxygen the organic materials self-heat; these in turn are placed into the cold frames and covered with soil, in which the crops are then sown. In this way I provide additional warmth for the plants, and our "frame" can now be called downright warm.
I chose the spot to face south, with the shelter and warmth of the house to the north. In recent weeks I had observed how, precisely in this spot, a lot of water collects, and the surrounding slope carries it straight to the foundations of the house. My idea is that, once I make the frame here, this water will be held by the straw, thus providing moisture for the sowing.
After a layer of straw, I tipped out a barrow of fresh pony manure, covered everything with cardboard and wetted it thoroughly with water, and on top I put another layer of straw.
I separated the straw from the soil with wet newspapers. The soil — in this case a soil-compost mix — is only about four fingers deep (about 7-8 cm), but I do not need more, because I will use the frame only to give a head start to seedlings of the earliest leafy greens — onion, leek, rocket, mizuna, spinach and some mustard greens and lettuces. By then I hope we will have built the greenhouse and I will be able to move them into it, and the "frame" will become a wonderful bed for early potatoes.
I shaped the sloping walls of the frame by untying one of the bales. There was enough of it left for the back as well, and the other I used whole for the front part. The wall of the house provides extra protection and will give off still more warmth from the most vulnerable, northern side.
I also thought of the mice, which adore straw shelters as well as young, juicy seedlings — I sprinkled, here and there among the straw, essential peppermint oil, which repels them.
The window frame for the very top I picked up from the street, where it had been thrown out — first making sure there were no cracks or gaps, so as to retain as much as possible of the heat accumulated beneath it.
The whole straw "frame", once it has fulfilled its role and I have moved the hardened seedlings out of it, can later be used as a bed, in which ready seedlings, seeds or potatoes can be planted directly in the open. The photo at the very bottom shows one such bed and the variety of vegetables it can successfully "feed".
The only thing needed is the proper conditioning of the straw bales over the course of about a week, with water and nitrogen-rich fertiliser — about which I will tell you in detail in one of the following posts.