Trying to make sense of wild winds and a weird winter

Obviously, the question of the week is how the heck trees survive winds like those we have been experiencing. I will address that.

First, however, I can’t remember such events in the past 50 years. Since when do we get warm spells with really high and persistent winds? Oh, the occasional taku, but goodness!

Maybe it is just being shut in by all the icy roads and high winds and the lack of real sunshine. I don’t know. I just don’t remember experiencing this. Of course, these days there are lots of things I don’t remember. Just ask my wife — ba-doom!

Where we live, windows last weekend were like teeth shivering, literally vibrating from the wind. Only it was almost 40 degrees. To think there are lots of reports of rhubarb thinking it is spring and emerging. Right now I am looking at the green leaves of some very confused strawberry plants.

Do I think this weird winter is an indication of global warming? You bet I do. And the rest of the world should be concerned because Alaska is the canary in the proverbial coalmine. It is just that warming is happening here faster than elsewhere.

More than once I have written of the staggering increase in the number of growing days in Alaska versus the seasons back when Charles C. Georgeson, Alaska’s first U.S. Department of Agriculture agent, started collecting records.

In Anchorage, the growing season now is twice as long as it was 100 years ago. We have added 15 to 20 days just since I started writing these columns almost 50 years ago. Corn anyone?

Yes, it is obviously very easy to drop from 40 degrees to minus 5 degrees in just a matter of days. And yes, there is a big difference between weather and climate change. Weather-wise, we have one weird winter. I still can’t help thinking the lack of a snow mass is not a good thing.

I also recall earlier than normal thaws weakened our spruce trees, making them so susceptible to the bark beetle. So back to those blowing trees. Scientists use words like “crown flexibility” or “wind-induced oscillation” or “elastic resistance” to explain how they deal with wind.

Garden columnists use “swaying” as the reason trees are still standing after big winds like last weekend’s. They have flexible trunks and limbs that are specially spaced to break the wind resistance. Some drop needles and branches if they have to.

Then there are the movements that create the sway. There are all manner of studies of limb trunk movements and oscillations during wind events. These change both in direction and in speed depending on the force of the wind and the location of the tree. That is why you usually see bouncing spruce boughs that twist and switch directions.

Obviously, something is working. Most trees withstood those hurricane-force winds. A good root system is also important, obviously. Here, where we have cold soils pretty close to the surface even in the summer, roots spread way out beyond drip lines.

Then too, trees are self-pruning. Wind events such as those we have experienced this winter prune trees: Dead limbs and branches drop to the ground. There they will decay — or get mulched by your mower — and their nutrients will be returned to the soil around the tree.

This is all truly regenerative. The smaller-size tree debris consists of the parts of the tree that contain the most sugars and nutrients.

This pruning is a way of dealing with wind because the loss of limbs reduces the surface area of the tree, making it easier to handle winds.

Of course, shedding of limbs also makes walking outside in high winds unadvisable. But who among us is Paul Bunyan enough to walk in such strong winds anyway. It is a much better idea to stay inside and watch how trees sway from the dry side of a window.

Jeff’s Garden Calendar

Alaska Botanical Garden: The Garden is not just for the summer! “Brighter Winter Nights,” Fridays and Saturdays, 5-8 p.m., through Feb. 22. Experience the magic! Ice sculptures, kick-sledding, model train, luminarias and more lights than ever! Get info at www.alaskabg.org

Valentine’s Day: Always plants available. Amaryllis again. Buy some.