Over the weekend I spent about 30 minutes piecing together a cold frame to do some hardwood cuttings. The process for building a cold frame is very similar to building a raised bed. I used some old pressure treated lumber that used to belong to a deck, an old storm door without the glass, and a couple 4″x4″ scrap pieces to make some secure corners. Pressure treated wood, depending on its age, may contain arsenic but newer pressure treated wood used copper based treatments to preserve it. Since this bed is for cuttings and not vegetables there’s no reason to worry about the arsenic. (I suspect the wood I’m using was treated with the copper treatment.)
I cut the wood to fit the storm door then used some 2″ deck screws to secure it to the corner posts. A flat surface is very helpful – mine wasn’t! Underneath the bed I laid a thick layer of newspaper to prevent any weeds from rising up and through the bottom of the bed. Then I placed a plastic mesh that I had on hand to protect my trees from deer. I have voles in my yard and I need to protect the bed from them. Most likely they will be able to nibble through the plastic but its what I had on hand. I may get some 12″ paving stones to place under the bed to discourage them further.
Once I had the bed itself in place I used the storm door hinge and screwed it directly to the bed. I need to come back and place a piece of plastic over the storm door opening. The glass went on my shed’s skylight a couple years ago so I don’t have that available. I’ll come back and fill the bed with a rooting medium which will probably contain a mix of peat, sand, and perlite.
From start to (almost) finished this bed took about 30 minutes to put together and could hold between 200-300 cuttings. For cuttings I’ll probably start with some viburnums and crape myrtles.