I am proud to say I worked for Howard Weaver. Well, not directly, as he never edited me, but he let these columns appear in the Anchorage Daily News and for that I will be ever grateful. I was a tiny, insignificant, little cog in the jeweled watch of an organization he managed and, 47 some years later, I am still so extremely grateful for it. I wear a pin that says “Write Hard. Die Free.” I got it from him. I keep trying my best, Howard.
[Howard Weaver, editor who led Anchorage Daily News through transformative years, dies at 73]
That is not how I expected to start this week’s column. What I want to write about, and will, is the recent announcement by the U.S. Department of Agriculture of a new Plant Hardiness Zone Map. It shows the low temperatures an area can expect to experience during winter. It is used to determine if particular perennial plants will survive winter in a given location.
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Every now and then someone asks me what Plant Hardiness Zone we garden in. Back in the earliest days of this column the answer I remember giving was Zone 3a, which is to say a low of minus 40 to minus 30 degrees Fahrenheit. To be sure, I would add some stuff about also being a change in daylight that the map did not factor in; it was temperature the government tracked.
I can even remember it used to actually get down to those temps. Remember, back in the days when we all had engine block heaters? For the newbies, the winters really have become warmer.
In fact, things warmed enough that in 2012, the USDA issued a new map. I can’t remember exactly what zone we were in, but it was a bit better so I would answer Zone 3b and laugh, because the uptick was nothing to write home about — nonetheless a column. It was an improvement, sure, but not so much as any decent perennial we would want to plant here would notice. After all, when it is that cold, what is a couple of 10 degrees one way or another?
Well, there is now a new, 2023 Plant Hardiness Zone map. It again shows improvement. It now turns out that most of us who garden in Alaska do so in Zone 5b. This means that some time during the life of an expensive perennial or tree, it can expect low temperatures between minus 15 and minus 10. That is almost survivable by many perennials. And, hey, add the protection of a bit of leaf mulch and, ahem, snow, which will trap in heat, and all manner of perennial possibilities actually open up.
Listen to the “Teaming with Microbes” podcast with Jeff Lowenfels and Jonathan White
The fact that this new map was issued so soon after the last update should end any doubts about global warming. Things are most definitely getting warmer. Just ask anyone growing peaches in Georgia. Last winter got too warm by “normal” standards and then there were freeze and thaws when plants blossomed; bye-bye peach crop. Alaska is losing salmon, so we know what that can mean to an economy and life.
Now, don’t get me wrong. For our purposes there is still a problem with these kinds of charts that may be unique to Alaskans. Even if a tree can survive our winters, which are now warmer, they are still longer than most. Can this new tree also prepare for the fast change in seasons? Our day length changes dramatically, up to six minutes a day. In tree time, that may be impossible to manage. Leaves don’t drop. Sugars don’t get proper storage. A tree which should grow in Zone 5b may not have the genes to actually make it in Spenard.
And this year, I would be remiss in not mentioning there are also snow charts that need updating, at least as far as Alaska is concerned. I found one that said Alaska averages 64.5 inches of snow. Hmm.
Jeff’s Alaska Garden Calendar:
Alaska Botanical Garden: Did you see the light display yet? Have you checked out the classes and workshops? Did you join and gift memberships like I suggested?
Snow load: OMG. Are we beyond able to knock snow off limbs and shrubs? Keep trying.
Indoor Christmas trees: Water! Water and water. Make sure yours is set in enough. And expect to recycle yours thanks to the annual ALPAR recycling program.