The snow is gone and it's possible to do an assessment of how sequoias survived this winter.
It was their first real winter, which turned out to be typically cold and reasonably snowy. Temperature-wise, it certainly wasn't a record breaking one on either side of scale but it's unlikely that the sequoias will be facing significantly colder conditions. Snow-wise, pretty much the same thing. Although there were several episodes when it was cold without deep snow cover, average amount of snow was not exceptionally low compared to most years and it was certainly far from dry.
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| February 2015 precipitation deviation from normal. Central Eastern Iowa had about 70% of normal. January was slightly above average. |
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The verdict is still out on how well sequoias faired but here is first observations the first weekend after intense snow melt. Temperatures jumped from 0F to 50-60F+ in two weeks with the warm weather now staying for about 10 days. Last 3 days the thermometer climbed to 70F with overnight temperatures of 34-38F.
The first observation was that of significant browning of both needles and the trunks. It was very clear that the parts exposed to air got significantly redder than the branches that stayed under snow. I uncovered some branches that were buried under the mix of mulch and ice that looked bright green. Most of the volume of all sequoias that was not solid frozen into that mix got much darker. On a closer examination it appears to be a mix of green and brown streaks, giving overall look of a dark "dirty" green color.
My biggest concern was with #15, one of the strongest samples. The way how the container was position on the slope it was very difficult to cover the plant with significant layer of snow. Also the "mini-cliff" formed by the ground and container on one side tended to create conditions that were allowing blowing the snow, exposing the plant. It is by far the reddest sample on the patch, with over 50% volume having almost pure light brown color.
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| #15 March 14, 2015 |
On close examination the light brown branches are not as thin as in the case when sequoias are dying due to the diseases. They look normal so to speak from the shape standpoint. Time will tell if it's a wishful thinking.
The tallest sample #34 also has significant browning but not as wide-spread as #15.
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| #34 March 14, 2015 |
A side by side comparison of CA 1 sample demonstrates color changes well:
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| #CA comparison between Fall 2014(on the right) and Spring 2015 (on the left). March 14, 2015 |
The pattern continues across all samples but some that were not as tall and were buried deeper and longer under snow show more green and less brown. #38 is one of several samples that managed to stay mostly green:
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| #38 March 14, 2015 |
Here is a sample of practically unchanged green needles that I found buried under mulch. I added about 4-8" right before temperatures started to fall below freezing, partially covering some lower branches of the plants:
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| A branch frozen in a mixture of mulch and ice |
The water accumulated in loosely spread mulch and then froze, capturing some of the branches. Once I discovered that these branches were hard frozen in, I stopped trying to remove them at this time. When they thaw out, I will check if it damaged or preserved them.
Overall, despite a very "dirty" look of the patch that emerged from under the snow, it appears most if not all sequoias have at fighting chance of survival.
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| Sequoia patch March 14, 2015 |
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