A very wonderful Vermont author, Howard Frank Mosher, died last week, just days after the publication of his final book, “Points North.” Mosher wrote many award-winning novels, as well as “Where the Rivers Flow North,” one of the finest novellas ever written; his milieu was Vermont’s Northeast Kingdom, where he’d lived since 1964. I think of him and the ebullient character in his novel “Disappearances” every time there’s a heavy snowfall in late spring because of the character’s optimistic proclamation, “This is the snow that takes the snow!” 

These last storms may not even be the ones that take the snow, and you probably don’t want to hear this as you clear off the car yet again, but snow really is good for the garden and soil. Snow contains nutrients that penetrate into the soil, including nitro­gen, some sulphur and other trace elements — thus snow’s reputation as “poor man’s fertilizer.” As all forms of precipitation fall through the atmosphere, they collect atmospheric nitrogen, but rains heavy enough to contain measurable nitrogen generally run off before nitrogen-fixing can take place. Lightning also adds a little nitrogen, but only in localized pockets where strikes hit the ground. Of the three, snow is the best form of natural nitrogen. Not only does it allow the necessary chemical reactions to take place in the soil, it also protects micronutrients and bacteria by blanketing the ground. However, the soil can only receive these benefits if it’s not frozen, so it’s primarily the late-spring storms that add nitrogen. Most of the nitrogen-laden snow that falls on frozen ground is lost as runoff since the soil cannot soak it in.



Snow also replenishes the water supply. You may have heard the saying that 10 inches of snow equals one inch of rain, but at higher temperatures, say a few degrees above freezing, when snow is often heavy and laden with water, the ratio may be more like five to one, with five inches of snow melting into one inch of water. Conversely, at lower temperatures, when snow tends to be light and fluffy, the ratio can be as high as 15 to one. How rapidly that snow melts is a factor in replenishment: a fast melt can cause flooding, overburdening drainage systems and sending polluted runoff directly into streams and rivers. But a slow snow melt means water trickles slowly into the earth, percolating through the soil and refilling aquifers. 

The term “blanket of snow” is not just a poetic description of a wintry landscape; freshly fallen snow is typically 90 to 95 percent trapped air that slows the flow of heat from the warm ground to the cold air above. This blanket effect makes snow an excellent insulator over the land, protecting both plants and animal inhabitants against frigid temperatures and damaging winds. Temperatures underneath a layer of snow increase about two degrees for each inch of accumulation. Because the soil also gives off some heat, the temperature at the soil surface can be much warmer than the air temperature.

And, if all these benefits don’t convince you that snow has some virtue other than providing a needed surface for recreational skiing and an occasional day off from school, organisms that live under snow help break down plant litter such as leaves and grass clippings and make more of the nutrients from that de­bris available for growth in the spring, when it finally, and inevitably, rolls around.