Jack Frost.

Around the gardens here in The Mission, we’re packin’ up for winter. As I write this, record low temps are due for the entire Bay Area tonight that dip below 30*. This frost is most certainly a game-changer for our greens. While there are many ways to prevent frost damage, luckily Amyitis doesn’t have all that much to protect at the moment. Most of our space is now occupied by frost-hearty cover crop or planted deep with garlic and potatoes. Some of these root crops have sprouted and I am curious to see how the frost affects them, the garlic shoots in particular.

In Vermont, November garlic plantings very quickly faced low temperatures and light. This didn’t allow them time to sprout before the snows of winter; they lay protected under the ground until spring. Here however, all of the garlic planted in November has seen the light of day due to our easy climate…. and now BAM! An edge event like this frost can be quite destructive for a region unprepared for such weather. I guess I’ll see tomorrow morning.

Frost occurs when a (deposition) surface temperature falls below that of the dew point of the surrounding air. Plants not protected by a thermal mass or with exposed foliage quickly fall below dew point temperatures on these extremely cold nights and begin to collect ice crystals. These ice crystals can destroy cell walls of many vegetable plants turning them black and rendering them “compost” within an hour.

Above and below are a couple of pics from a potato planting day. The cut halves of the seed potatoes are dipped in ash ( highly alkaline) to prevent seed rot. Tomorrow I will be experimenting with potato towers to examine the difference between methods.