When you have an itchy green thumb and spring seems a long way off, cold frames start to look really good. Krista has long been an advocate of building some for our yard, although I have been a little lazy about it because I’m focused on other stuff. But during our visit to the NW Garden & Flower Show this weekend, I got a metaphorical bee in my bonnet about cold frames. We might be building some as early as this weekend.
Cold frames are a good way to extend your growing season – either into the fall/winter, or starting earlier in the spring. They generally have sides that block the wind, and some kind of lid made of glass that can be propped open for ventilation. Place the cold frame facing south if possible, and put the glass on an angle to capture the most sunlight. I most often see old windows repurposed into cold frames. Open the cold frame on warm, sunny days to avoid cooking your plants. We’re fortunate to live in a place with a relatively mild winter, so a few cold frames might be the answer to our need for year-round, garden-fresh produce. The idea of a cold frame is so basic, I’m not sure why we haven’t built a bunch already (oh, just sheer laziness).
This lovely, flowery cold frame came from the Arboretum Foundation’s Winter Garden ( i think), or maybe it was the First Breath of Spring garden from the Puget Sound Flower Growers. I can’t remember, unfortunately. This cold frame looks pretty sturdy, and that device for propping it open is fancy – I would probably use a stack of old bricks or a mossy stick from the apple tree. This is the type of cold frame you could lift off when freeze danger passes, and put in the garage until next year. The construction is fairly simple – if you can cut a diagonal line, and handle a hammer, nails, screw driver and some hinges, you could probably make this in an afternoon.
Seattle Tilth & Jessi Bloom build a great “little farm in the city” in their demo garden, and it included this cold frame. I love that it’s painted a bright cheery spring green. Fancying up a garden is highly valued in our house. An old wheel props it open, instead of a custom propping device. It’s hard to see from this angle, but this cold frame is full of dirt – this is the kind of frame you need to leave in one place, not pick up and put away. The dirt is close to the glass. I love that it is a highly functioning container. Since there’s not a lot of headspace, once those seedlings get going, the glass should be open to let them grow. This would be most useful with slow-starting spring plants, who need help getting starting but can handle being open to the elements pretty quickly. You might make this so that the glass comes off completely in the summer but reattaches next spring.
This style of cold frame was assembled entirely from recycled materials in the RE Store space. Old bricks, cinder blocks, and an recycled window are all that’s used to piece this together. Even I could make one of these! There are some gaps around the edges, so be more careful with the corners if it needs to stay warm in the winter. This is ideal for early spring and late fall growing. It would be more of a pain to re-locate than a solid wood frame, but you could theoretically move all those bricks to any location you desired. The best thing is the price tag… this could be assembled for free if you can scavenge the materials.
And finally, branching out a little from the cold frames, we spotted a propagation bench in the RE Store exhibit space. This is basically a cold frame on legs used to start seedlings. This is also made from recycled and reclaimed materials. This might help us bridge the gap between now (no all-season outdoor growing space) and the day when we buy/build our dream greenhouse. Krista suggested that we build a series of propagation benches to serve as a mini dog run / roofed dog area, and I thought that was brilliant. Have you met our dogs? They hate precipitation. Since we live in the PNW, this makes for miserable little dogs 5 months of the year. A dog run+propagation bench could bring harmony and joy to our household, in so many ways.
Do you any cold frame gardening? Do you have any advice for me?