I have built a straw bale cold frame before but we never had such cold weather as this year. We just experienced a “polar vertex” and had one night and one day where the temperature stayed at 0 degrees for long periods of time. With the wind chill factor it was actually much colder than 0 degrees.
The Straw Bale Cold Frame Didn’t Work So Well
Today we are at more normal temperatures for this time of year around 32 degrees. You can see from the picture above that my arugula looks like it survived the polar vertex quite nicely but after a few days I saw that only a few plants survived. It took a while for them to die. I think it is possible that if I would have covered it with a quilt or piece of carpet the arugula might have survived better. There were some small openings and if the cold frame was covered with an additional cover it would have fared better. Next time I have the opportunity I will test this out.
In my last straw bale cold frame I didn’t have such a good cover. I used to use a screen door frame covered with a light row cover. Now I have plexiglass that is very sturdy and holds the snow off the plants. Plexiglass is very expensive so if you can get some used it is cheaper. I got mine used.
Arugula is Considered a “Bitter”
Arugula is quite bitter with a peppery mustard taste. I like to eat it because it is considered a “bitter” and can stimulate the digestive system. See this article Bitter Herbs Sweeten Digestion. If you are thinking about what to plant this spring Arugula is a great plant to start early. Last year it did great when the temperature was in the teens. And it is nice to have such fresh greens as early as possible!
The Lettuce Didn’t Do So Well
My lettuce didn’t fare so well. It is in a pot on the front porch. It has survived three snowstorms but it doesn’t look like it survived the 0 degrees. Of course, it was not protected by anything. After a few days it looked much worse than in this picture. Completely black and dead without much hope for any revival. This picture could have fooled me. It took a few days for it to actually show the damage.
The last thing I learned from this polar vertex is that Daffodils are very hardy. I already have a few poking up above the soil. To me this seems extremely early because I first saw them in December. I wondered how they would do with the extreme cold temperatures. To my great delight they look great. Here is a picture of one of them. As you can see from the picture it did not have much protection like autumn leaves covering it up.
A straw bale cold frame is easy to create. At the end of the winter you can use the straw to create a compost pile or use it for mulching around your plants. And then the next winter you can make another one!