The Cold Snap & Spinach
Spinach is, by far, our most reliable winter crop. It can withstand temperatures that defy expectations and we’re still learning what its limits are. We just came out of a two week stretch of cold with temperatures rarely getting above 0*F. Our lowest recorded temperature was -20*F. According to some meteorologists, this stretch of cold weather was the coldest stretch of weather we’ve experienced since 2019. We’ve been growing winter spinach since 2021 so it begged the question of would our spinach survive this cold?
The short answer is yes, the spinach survived, but there’s a catch. The catch being that while the spinach did survive the cold snap it did not grow during the cold snap. Part of our winter spinach plan is to get some growth even during the cold. We’re not expecting dramatic growth but enough where in 4-6 weeks time spinach can regrown into something we can take a second harvest from. We may harvest some spinach for our upcoming market but we really want to be careful to make sure we’re not selling ourselves short for future markets.
The next question is how exactly does spinach survive this kind of cold? I’m not a biologist so this is purely based on observational information and is just my anecdotal evidence but I think it largely has to do with a defense mechanism spinach has. When it gets really cold, usually below 0*F, the spinach in our tunnels wilts. It looks like what would happen if you dumped a bag of spinach out on your counter and left it out overnight. Limp, dreary, dull color and seemingly not salvageable.
The really cool thing is that the spinach in our tunnels perks back up once temperatures rise for several consecutive days. It seems to me that the spinach plant drains its leaves and stems of water and presumably stores the water in the soil as a way to protect itself from the cold. This is why it looks like its wilted. Then, when temperatures rise the spinach plants uptake that water and it looks good as new.
When we pair that plant adaptation with growing the spinach inside a tunnel and use floating row cover to protect against the coldest of the cold temperatures we suddenly are able to grow spinach all winter long!
