How to Make A Cold Frame Step-by-Step
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How to Make A Cold Frame Step-by-Step

August 23, 2019

[Music] Cold frames are an essential part of the gardener’s toolkit. Use them to start off seedings earlier in the spring, to carry on cropping vegetables well into winter, or to help harden off tender plants in early summer. They really are the gardener’s best friend! If you don’t fancy splashing out lots of money on buying one – don’t! Because in this video we’ll show you how easy it is to make your own. A cold frame is simply a box frame with a clear lid on top. The frame is normally constructed from wood, but other materials such as blocks or bricks are also common. The clear lid lets in the sunlight, trapping warm air inside while protecting plants from inclement weather. Because of its uncomplicated structure, a wooden cold frame makes an excellent DIY project. Salvaged windows will give you an instant lid, with the frame measured and cut to fit. Slope the lid towards the midday sun for maximum light and warmth. Position your cold frame directly onto the soil or on concrete or slabs. To make a cold frame, start with an old salvaged window or windows, or a clear door such as a shower door. If you cant get one, use a sheet of glass or twinwall polycarbonate secured to a simple wooden frame. To fix the lid to the walls of the cold frame you will need some strong hinges To make demonstration of the construction process clear, we are using a cold frame kit. If you are using a salvaged window for your cold frame, then the wood for the frame will need to be cut to fit. The box that the lid sits on is made up of lengths of pressure-treated lumber cut to match the dimensions of your lid or lids. Here we’re using three boards at the front then four the back to give us our slope. Seven shorter boards make up the sides. The seventh length is cut diagonally to give you two triangular boards, one for each side to match the slope. The boards we’re using are about three quarters of an inch (19mm) thick. All of the boards will be screwed to four corner battens about an inch (2cm) thick which match the height of the front and back of the finished cold frame. You will also need four additional battens – two short and two long – which will enable you to either vent the cold frame or fully prop open the lids on sunny days. To put the frame together you’ll also need some wood screws, a drill, and a screwdriver. Begin by making the frame. Screw the side boards to the battens using two screws at both ends of each board. You will find it easier to drill pilot holes before screwing the boards into place. You will need to screw the narrow end of the top board down into the board below like this. Now for the front and back boards. Screw the front boards into the battens, again using two screws at each end of each board, Then turn the frame around and screw the back boards into place. The completed frame is now ready for the lids. Carefully position the lids onto the frame so the lid and frame are flush at the back. Now screw on your hinges. Longer lids may need several hinges along their length. The only thing left to do now is to screw the lid support battens into place. If necessary, you can also screw some handles on the front ends of the lids. And there you have it! Your cold frame is ready to use. Cold frames can be used to overwinter tender perennials, to grow winter salads, or get a head start on the growing season. For example, strawberries grown in a cold frame will be ready to pick a whole two weeks ahead of those grown outside. Cold frames are also excellent for starting off tender crops such as squash or use your frame as a halfway house between greenhouse and garden to toughen up plants before they’re planted out. Our Garden Planner cleverly shows how growing conditions shift within a cold frame. Let’s start by selecting a cold frame from the structures menu. We can then drop the cold frame over our crops and adjust it to the exact orientation and size of the cold frame. We can now see the effect this has had on the accompanying Plant List. Comparing lettuces with and without the protection of a cold frame we can see that the lettuce in the cold frame can be sown, planted and harvest a full half a month ahead of the lettuce outside, while the harvest period is extended by a similar length of time. Make a cold frame and you’ll dramatically extend your growing season which, as a gardener, is great news! If you’ve got a cold frame, tell us what you like to grow in it by dropping us a comment below, and for more practical projects and growing advice, don’t forget to subscribe. I’ll catch you next time. [Music]

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  1. I don't use treated wood around plants I'll eat. It's not necessary unless it's buried (at least here in Colorado) and the chemicals can leach out. Cedar or redwood is a better choice IMO.

  2. I want to make a strawbale coldframe for my watermelons next year. twentymillion other plans also still on the shelf so yeah… Maybe i will, maybe i won't.

  3. I need to learn to do this . Seriously
    Excellent project First I need tools I dont even own a drill or hammer .
    I'm laughing but its not funny . Of course you can get some handyman to do this
    However Id take great pride building it my self and enjoy it it GREATLY
    Id like to grow baby leafy greens and Herbs in this

  4. I won't use pressure treated lumber in the gardens as it leaches toxic chemicals into the food. Nor will I use redwood, a natural toxin.

  5. Thank you for the suggestions, advice and instructional video.
    I'm fortune in that a friend gave me MANY (10-15?) glass panels which once went around his jacuzzi enclosure, but at the time I hadn't and real good idea (s) about what to do with them.
    Now all I need is to acquire the lumber and screws with which to build the boxes. Then I need some decent soil and I'll be ready to go.
    Two questions, if I may ask.
    1. Do you recommend placing small holes on each end or side and cover them with a screen that is small enough to keep out bigger pests like birds but also large enough to permit the entry/exit of bees, etc., as desired, and,
    2. Would it be advised to incorporate some kind of grow lamp that puts out a modicum of warmth, along with lighting to help on dreary days and if so, where might I find information on the size, wattage and times it should be used?
    Obviously, not knowing my specifics it would be difficult to make solid suggestions but if you could speak in general terms it would be most helpful.
    Again, thank you for your time and efforts to educate your viewers (and fans!). 😎

  6. I'm new to your channel (?), anyway, I saw you had a layout for gardens and which veggies go well with others, where do I find that?

  7. Can the same effect not be had by buying a big clear storage box from a discount store and just covering your plants with it? Weigh it down with a brick to stop it flying off, drill holes in it for ventilation or just leave a small cap at the bottom.

  8. Hi. If you want to build it yourself just google for 'Woodprix' . I know you'll find good solutions for your idea.

  9. One year I made a cold frame by using leftover potting soil bags filled with compost for the walls and an old glass table top for the lid. Lovely, unfrozen lettuce in the middle of winter!

  10. So place on concrete or grass please?
    I would think on grass you have to deal with grass and weeds growing inside the frame.
    Not to mention the fact that this would also be a heated slug hotel if on grass.

  11. Your glazed roof will trap rainwater runoff between the glass and lower frame leading to the wood rotting very quickly. Better to allow the glazing to only be sandwiched in the frame on three side and to allow the glazing to overhang the lower wooden support. The glass will be secured by adhesive sealant or polycarbonate can be drilled and screwed.

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