In Seattle there is less than an inch of snow on the ground. At my house, further North, we got a dusting. Local media outlets call events like this “BLIZZARD WATCH 2012″ and “SNOWMAGEDDON.” People who went to college in Minnesota or grew up in Maine get their chance to drone on and on about how Seattlites can’t drive in the snow. (This is true, we can’t, but we totally own puddle driving.)
Snow on the ground universally means cold. It’s a visual reminder than temperatures drop below freezing, and that can give year-round veggie gardeners the willies. But, in the Pacific Northwest at least, snow rarely comes with plant-destroying low temps.
There are exceptions, of course, but in general the thick, low, heavy cloud cover that tends to brings in the heavy, wet snow typical for this area acts as a sort of “Sky Cloche,” trapping in whatever meager warmth managed to accumulate over the day and preventing night time lows from dropping too painfully low. Snow itself acts as a mulch, of sorts, too, moderating temperature changes over the course of the day. And generally, what snow we do get is gone quickly.
No, what we cold-season veggie gardeners really need to be careful of are the cold, clear days. They aren’t as common in this land of silver drizzle, but occasionally we get a winter day that looks just sparkling: blue skys, one or two high, puffy clouds, sun streaming low but bright into the windows.
With a mania likely induced by Vitamin D deficiency, we pour outside into the sunshine, convinced spring is finally here and it must be fifty-five degrees out (that’s running shorts temperature in Seattle). We stare at that unfamiliar glowing orb, only to realize, “Hey! it’s damned cold out!” It’s snot-running-down-our-red-nose cold. It’s even-my-latte-can’t keep-my-hands-warm cold. It’s why-the-hell-didn’t-Cliff-Mass-tell-me-it-was-this-cold? cold.
So back inside we hide, feeling just a bit tricked. Half of us go skiing. Half of us use the cold as an excuse to add bourbon to our coffee. We all feel better, but meanwhile, our plants are dying.
The combination of deep cold and dry air will take down all but the hardiest coles and semi-hibernating garlics. Everything else is at risk. Root crops that freeze hard will often rot as they thaw. Leaf crops can tolerate only so much, and they’ll go to mush too. Overwintering favas will die back. If they return, they’ll be severally weakened. Herbs that normally grow like weeds in the protected Maritime Northwest will give up the ghost – I’ve lost rosemary this way.
The weather people are saying we Seattlites will see additional snowfall for the next few days. If you’re still nurturing a winter garden, take comfort that if it’s made it this far, the high-20s/low-30s temps that will accompany this upcoming blast of white probably won’t do your garden in. The one thing you want to watch out for is heavy snow crushing your plants, collapsing your cloches, or blocking light into your greenhouse.
This is another advantage of tunnel cloching your plants: the protection from direct contact with snow, pounding rain and hail provided by the cover. If you do see major snow buildup on some prized trees, herbs or vegetables, just brush it gently aside while you’re outside making a snowman with your kids.
And as we enter the final stretch of what has, up to now, been a very mild winter, keep your eyes out for those clear, cold snaps. They’ll knock your garden down to the mulch faster than any Seattle snowfall. Let it snow, let it snow, let it snow!
If everything does go white on us, drive safe out there. Or better yet, don’t drive at all. Even if you know how to handle snow and ice, chances are the guy next to you doesn’t.