Snow is a welcome sight in the garden.
It covers up any design mistakes you think you’ve made, or areas that need rehabbing and gives the garden a clean slate for winter dreaming.
We haven’t had much snow yet, but papery “Limelight” hydrangea blooms, sedum heads and the gnarly kiwi vine are lightly dusted with white stuff resembling powdered sugar sprinkled over cookies still warm from the oven.
My terriers, Andy and Ollie, slink under bushes and trellises and across garden beds, their noses stuck to the frozen ground, picking up scent trails. Our resident squirrel occasionally risks darting into the backyard for black walnuts, once hidden beneath foliage and now exposed to its beady-eyed gaze from atop the fence posts.
Squirrel-schmuirrel … Forget that fuzzy-tailed rodent, says Lucy, my beagle mix. Her vision isn’t good these days, and she prefers to cool her jets on the porch until the back door opens. Then she dashes indoors, stopping for a treat (hopefully) on her way to a snooze in her fleecy bed.
More snow may fall by the time this column is being read, but in any case, snow is nearly always described as a good garden insulator. It prevents plants from heaving out of the ground in the freeze/thaw cycle. But have you ever wondered how it works — how snow actually protects plants from the cold?
According to an article at the National Gardening Association website, “it happens because of the way snowflakes are shaped. There are small spaces in each one that are filled with air. As they pile up, the result is low heat conductivity so the daily temperature permeation into the snow is reduced, and the plants are protected from really cold temperatures.”
NGA also suggests that without benefit of snow cover, “cold temperatures can freeze the ground deeply, which damages the root systems of shrubs and trees. Without insulation, the water contained in plant cells can freeze, damaging the cell walls. Plants can turn black or look translucent.”
Interestingly, NGA notes that the natural cycle of freezing and thawing actually improves soil structure and makes it easier for plants to set down roots.
Snow has earned the name “poor man’s fertilizer” because snow gathers nitrogen and sulfur as it falls to the ground. When the snow melts, these elements are absorbed into the ground as perennials begin awakening in the spring.
In addition, folklore points out that roses flower more profusely and apples and pears set more fruit in spring, after good snow cover in winter.
The Japanese, NGA says, revere snow and use special snow viewing lanterns called yukimi placed in their gardens. Snowflakes on tree branches are called sekka, or snow blossoms.
Winter winds also will desiccate plants, and a layer of snow protects against that drying, frigid air. Mice and voles will use snow cover to dine on shrubs and tree trunks, as well, NBA points out.
If the snow is particularly deep, rabbits and other rodents will have a fine time pruning plants or gnawing on tree trunks. I recall a winter of heavy snowfall that did a good job covering a long row of bridal wreath spireas. But rabbits still did a bang-up job of pruning. After the snow melted, and I could get a good look, I realized all seven spireas were “pruned” to nearly identical heights. Of course, there were few blooms that year, thanks to the rabbits’ zealous munching.