The Greenhouse is Where it's at
The beautiful greens we planted just in time in the fall grew nicely and are now gracing the Winter Bounty CSA baskets each week.
Did you know that the greenhouse at this point is actually a giant fridge for the greens living there! The truth is most plants don't grow with less than 10 hours of daylight. Even if the temperature is kept within the optimum range — for example, in a climate-controlled greenhouse — most plants will just sit dormant until the magic 10 hours of light per day arrives.
Guess how many hours of daylight we are enjoying these December days? 8hr 49minutes. This means in our greenhouse the plants are sheltered from the wind (meaning they stay warmer and don't lose their mositure too quickly) and because we don't use artificial light they are basically staying healthy (but not growing) until we pluck them from the earth for your basket!
The particular greens we chose for the greenhouse are amazing at withstanding cooler temperatures, in fact, they thrive at cooler temperatures between +5 and 15*C and can survive temperatures down to -10 or more as long as they are protected from the wind.
In the greenhouse, we even add a second layer of protection in the form of a light weight row cover fabric. (like an additional blanket.) The GH also helps them survive by making sure that they don't stay frozen too long. for example, the other day it was -5 outside and +12 inside.. just with the heating power of the sun!
Another cool fact about greens that do well in cooler temperatures is that as the temperature drops below 0*C the plant is stressed which causes it to create sugars (to reduce its chance of freezing) resulting in super crisp, sweet arugula, spinach, kale, braising greens, baby romaine lettuce and mixed greens!
In order of least frost hardy to most.... lettuce, arugula, asian greens, spinach, kale.