All of Wyoming was enjoying a superlative Indian summer throughout October and the first two days of November with pleasant temperatures approaching seventy degrees. Then the bottom fell out. In just three days the temperature plummeted to twenty or more degrees below zero—an eighty to ninety degree temperature drop.
So why bring up last November’s temperatures in a gardening column in April? Well, those three days in November are the equivalent to an atomic bomb being detonated, horticulturally speaking.
As I’ve mentioned before, plants survive winter’s worst by developing plant antifreeze, they increase the sugar content in their cells while reducing the amount of water. All that sounds great, but the reality was in early November they hadn’t reduced the amount of water in their cells.
Any physics professor will tell you that when water freezes it expands. Inside a plant cell, the water froze, expanded and burst the cell’s wall. In terms of humans, it was akin to hemorrhaging.
The first outward signs to express themselves were in our evergreens, namely pine and juniper. The needles froze with too much water stored in their cells. The result is burnt orange needles we’ve looked at all winter long.
The hardest impacted plants were shrub junipers. Many will not survive this atomic bomb. I’m giving the pine trees a 50/50 chance of surviving. We will all know for certain in thirty days or so as these plants begin their normal spring green up.
Now gardeners are inspecting their landscapes and realizing that there are a slew of deciduous trees and shrubs failing to develop swelling buds. Just like in our evergreens, our deciduous plants had too much water stored in their cells and they have died back.
At my garden center I have successfully grown a cold tolerant peach tree for five years. This spring I noticed its branches have died back along with its primary leaf buds.
I am hopeful that as spring marches forward, secondary buds will emerge and the tree will continue to support my peach habit.
I am advising gardeners with similar situations as with my peach tree to remain patient and let the tree or shrub show you what’s living or dead.
Trees and shrubs are a lot like warships. Just because a torpedo hits the ship doesn’t mean it’s going to sink. Ships have redundant backup systems to stop the flow of water into other compartments of the ship. So, too, do trees and shrubs; today their primary leaf buds are toast, now let’s see what the secondary buds will do.
In my professional career, I have never seen the likes of this winter devastation. And to think we had the mildest winter on record.
Originally published in the Casper Star-Tribune, April 19, 2015