The warm weather in November has got me in a gardening mood, so I decided to build a straw bale cold frame with the windows I found earlier this year. I got 10 straw bales at the local feed store, a couple of 10 foot 2 x 6 and I was ready to go. First I arranged five strawbales in a U shape facing south.
This was across some existing beds, so the soil’s already in good shape. My goal is to grow hardy salad greens in here over the winter: cress, sorrel, spinach, lettuce, chard, chickory. I raked out the mulch a little to create a good seed bed.
I bought a thermometer at the local hardware store to hang inside.
Next, I put the 2 x 6 boards across the opening and placed windows across these for the top glazing. The windows appear to be insulated double-pane with some UV filter. They’re 34″ square, so the full opening is 102″ wide.
Now the second tier of straw bales. According to Albert Bates of the Farm, water soaking into the bales over the winter will start them decomposing, and this process will add heat to the cold frame.
The footboard at the bottom is two scrap 4 x 4. This will keep the front angled windows off the ground to help keep the frames from rotting. The full area under glass will be about 8′ x 5′. At this point I sowed the seeds and covered them with a fine dusting of my seed starter mix (leaf mold, potting mix and sand). Next the front windows go on.
Finally, I blocked up the open ends with extra straw from the 10th bale (top tier is only four bales).
- 6 windows- free
- 10 straw bales: $59 (could’ve shopped around and got them cheaper)
- 2 10′ 2 x 6: $10
- thermometer: $7
In total I spent about 2 hours gathering materials and about an hour putting it together. Will let you know the results later this winter!