As I write this, it is Nov. 10 and the temperature outside is about 15 degrees. That’s cold, man! Even for Minnesota in late fall. The rather sudden drop in temperatures over the past couple of weeks has many gardeners wondering if we are in for a “real winter,” meaning one with lots of cold and snow.
The last time we had a significantly cold and nasty winter was 2014, when Minnesota schools were canceled for five days because of vicious wind chills. In 2016, I experienced the earliest first bloom in my Northfield garden ever with a bloom on March 13. That was also the longest growing season on record and we did not even have a frost in the Twin Cities until Nov. 7.
The National Weather Service has predicted the possibility of a weak La Nina system affecting weather here, which indicates it will probably be cold and wetter than normal. What does this mean for gardeners?
If you still have fall garden work, get it done! I still have a few garden chores to do, including adding shredded leaves to my beds and cleaning out a few pots of annuals that I have not gotten to yet. It looks like this coming week will have a few slightly warmer temperatures and I plan to get out there ASAP to finishing things up.
Fewer bugs??? Well, that’s the hope when we have a cold winter—that it will be cold enough to zap the Japanese beetles and other invaders that spend winter in the soil. Experts say that how much of the population of pest insects are killed by cold weather depends on 1) how cold it is and for how long; and 2) how much snow cover we have and when we get it—cold weather without snow cover is more likely to kill grubs nesting in soil. This article notes, however, that cold, dry winters also kill beneficial insects and, sadly, that Japanese beetle grubs can go very deep in the soil. Sigh.
More plant losses? Well, maybe, maybe not. We had a lot of rain this fall, particularly in October, which means plants are well-hydrated going into the winter season. With this early freeze, you could mulch around tender plants to make sure they don’t heave out of the ground during the inevitable thaw-freeze cycles. But, if we get some decent snow in December, we may just be in for a long, long winter.
Time to make some tea and get out a book!