March is really not the traditional time to discuss preparing our gardens for harsh, mild, or simply unpredictable winter weather. Yet, I’m sitting here looking out at a sunny, cold, and blustery February afternoon, with no snow protecting my gardens and pussy willows already emerging from the tree branches. I’m thinking, and really hoping … Did I do enough to ensure my peonies, planted last fall, survive the winter? With the extended warm spell we experienced in January, plant survival is a topic on many Alaskan gardeners’ minds. What more can we do now and next year to ensure our perennials and bulbs survive our crazy winters? 

It is not sub-zero weather that causes problems for bulbs and perennials in Alaska, but fluctuating soil temperatures. Plants go into their natural hibernation period when the days grow shorter and the ground freezes. Freezing does not hurt them … if they stay frozen. Once the ground has frozen in the fall we need to do what we can to insulate garden beds to keep them frozen throughout the winter and spring, especially if we have newly planted perennials. In a perfect winter we would be able to count on nature’s best insulator – snow. Have you ever observed a neighbor shoveling snow onto his or her garden beds in the spring? It may look crazy, but gardeners who keep their perennial and bulb beds covered as long as possible, even through April and early May, are very wise. 

In an ideal seasonal weather pattern, the ground thaws in the spring and plants begin their natural growth period. When the ground thaws in January, followed by normal winter weather, it can be disastrous, even for typically hardy plants. Most Alaskans are well aware that “perfect” winters are rare. Much of Alaska has a maritime climate and, combined with mountain ranges and other terrain, the weather here varies dramatically. Temperature differences of 10-20 degrees or more within just a few miles are normal. Chinook winds bringing warm winter temperatures are not uncommon, so gardeners can rarely count on snow to stick around for as long as we want it to, especially at lower elevations. The average high temperature in January, usually the coldest month of the year in Southcentral Alaska, is 22°F. However, a quick review of temperature records shows higher temperatures in January are not so unusual. There have been many years since 1915 when days in January reached highs in the 40s and even the 50s. In 1949 the average high temperature record for January in Anchorage was 38.7°F. The average high temperature in Anchorage for January of 2014 was 33.8°F and other weather stations nearby in the Matanuska Valley reported average high temperatures for January at close to 40°F. The Matanuska Experiment Farm weather station recorded highs over 40°F for half the days in January with the highest temperature of 57°F on January 27th.

In an ideal seasonal weather pattern, the ground thaws in the spring and plants begin their natural growth period. When the ground thaws in January, followed by normal winter weather, it can be disastrous, even for typically hardy plants.

So how do we keep the ground frozen when Alaska’s fickle winters do not cooperate? I like to use spruce boughs for my beds. They are plentiful where I live and heavy enough so the winter windstorms aren’t a problem. Snip all the limbs off your Christmas tree and toss them on your frozen garden beds instead of hauling your tree to the local landfill. I find the spruce boughs are easily removed and can be burned or chipped in the spring. Many people use straw, but if you do be sure to secure it well. Chicken wire or some other type of fencing weighted down or pinned into the ground will work. Our 80 mph plus winter wind gusts, like we are experiencing as I write this article, will quickly whisk away any mulch that is not heavy or secured well. Garden beds on the southern sides of our homes are often reserved for sun loving and sometimes less hardy plants. Since the snow melts more quickly in these areas with favorable sun exposure, they need even more winter protection than shadier north facing beds. 

Another solution to prevent the winter loss of plants is be sure to choose varieties that are proven to be capable of withstanding Alaska’s climate zones. The Cooperative Extension Service provides recommended variety lists for the different climate zones in Alaska. USDA Hardiness Zones in Alaska range from 1 to 7, but within each of those zones are many micro-climates. What survives in your friend’s garden may not survive in your neighborhood, even if it is only five miles away. Your local greenhouse can provide excellent advice on reliable plant selections for your area. 

I lost a few perennials last year and am expecting this year’s losses to be worse. My main solution for possible loss of more perennials this year is to start more seeds than I usually do … hardy seeds. Many of my garden beds need refreshing anyway. I tend to let my perennial garden beds go wild so they often look a little straggly and are not well balanced with color throughout the summer. If I end up not needing all the extra starts, I know I will have family and friends who will be happy to give them good homes. The summer of 2014 is going to be a good year to rejuvenate my perennial garden beds so I have color all summer instead of for just a few weeks. Today I received my mail-ordered seeds from Anchorage based Denali Seed Company, so my next task is to set up my seed starting schedule.

And if the peonies I received from a good friend last fall don’t survive our winter’s warm spell(s), I know that our local Jacobson’s Greenhouse, just down the street, will have a wide variety of peony plants available for me to choose from.