That recent cold snap was a surprise, with temperatures well below freezing and the first snowfall in some areas. If your winter veggies were not all mulched by then I doubt they came to harm as the soil was still relatively warm. In this warmer lull, however, do get the mulching done before temperatures drop again. Mulch is especially necessary to protect the shoulders of root crops poking above the surface, but it also protects soil from erosion in heavy winter rains. I always set aside a big bag of leaves to use at the last minute, just before a really cold spell, to cover over top of the leaves of carrot, beets and other root crops. I wait as late as possible for this because I don’t want to smother the leaves prematurely (or provide rats with a tempting winter nest).
I know for a fact there are still people out there that haven’t planted their garlic and it is still not too late, but do get that done now while it isn’t so cold. No matter how late you plant garlic, it will always be better than waiting until spring.
The latest Climate Prediction Centre forecast is for a 65-75% chance of a weak La Nina pattern throughout the winter, which for us means rather cooler and wetter than normal. But since normal weather is a disappearing concept, just be prepared for whatever, including a re-run of last winter’s cold weather. Maybe this will be like the winter a few years ago when an extreme cold snap in November was the only cold weather we had for the rest of the winter….
A reminder on harvest tips through the winter: the hardiest leaves of lettuce, chard and other leafy greens are the youngest ones, in the centre of the plant. Therefore to get the most from your harvest, when you pick take the oldest leaves each time. Picking one or two leaves of each plant, instead of cutting all leaves from a few plants at once, also maximizes the yield. Leaves of hardy greens wilt in the cold, but recover when it thaws and they are able to get water from the soil again. Even if the leaves appear to freeze solid, they should be OK if you wait until the weather warms enough to thaw the leaves before harvesting. I am sure you have noticed how well most things came through the recent cold despite looking flat and wilted for a few days. Once again the difference between frost hardy lettuce and summer varieties was evident in my garden: leaves of the former are perfect in tonight’s salad, while the latter are water-soaked and decomposing.
I won’t be sending out alerts in December so please keep an eye on the weather forecasts for temperatures that could dip below -5oC (23oF). That seems to be a danger point for many hardy leafy greens (though kales, corn salad, parsley are not harmed at those temperatures). If colder weather is forecast, cover beds of greens with plastic sheeting or tarps held down with something heavy (Arctic outbreaks usually bring strong outflow winds to the coast). If lows look like they may go to down to -9oC (16oF) in your area, then cover winter cauliflower and purple sprouting broccoli for the few days of the cold snap. It has to be colder than that to daunt kale or the super-hardy ‘Unique’ variety of leeks, but most leeks varieties will benefit from covers if it gets that cold. Don’t worry about your mulched root crops: even last winter’s prolonged extreme cold didn’t harm them in most gardens. For more notes that might apply to winter conditions, check my archived messages, in particular the Dec. 19, 2016. Oh, and don’t forget to stake up cabbage family plants to prevent plants from being broken or ripped out of the ground by wind. If plants are already tipped, just brace them where they are to prevent further damage.
Spotted wing Drosophila update: Astoundingly, I caught 2 adult flies in my vinegar trap Friday after no catches during the cold and snow. These darn flies are pretty tough—it went down to -3oC (26oF) in my yard last week. I will continue to trap for a few more weeks to eliminate as many as possible before winter (see my Sept. 3, 2016 message). Numbers of SWD in 2017 generally were down all around the region, most notably in colder areas. Gardeners in Victoria and Vancouver, however, found maggots in their June strawberries so some flies obviously survived the cold winter in the urban environment. In colder rural areas, gardeners I talked to reported that SWD numbers only built up late in the season, if at all. I caught none until Sept. 10, a far cry from 2016 with catches starting in early August, peaking at 50-85 per day in Sept. and continuing until Dec. 11 (when you might recall, everything froze solid).