Yesterday afternoon I headed outside to shovel and play in the snow with the kids. Jordan had already been out for a few hours earlier with my husband and they cleared off most of the driveway with a snow blower and hand-shoveled the front walk. More snow had fallen since then, and Jordan was ready to tackle the driveway again, but I suggested hopefully that Jordan could help me shovel the path to the compost bins.
The previous year we did not keep up on the paths to the compost bins so after a few cumulative snowstorms, the outdoor composting was sort of written off for a couple of months. This year I would like to keep the outdoor one going because they can handle a much larger volume of material than our indoor worm bin.
Jordan enthusiastically agreed, and he blasted off shoveling the path all the way to the bins in a few minutes. I don’t know where his energy comes from! While I was following behind him, much slower, getting the bottom couple of inches, he said he wanted to go all the way from the bins over to the steps and also clear the steps up to the garden. Then he went and did that in short order as well. Lauren also had a shovel and was cheerfully following me around trying to help as well.
While we were shoveling the snow off the steps and tossing it into the terrace gardens, I started thinking about the idea I’d heard that snow is a good fertilizer, and I wondered if that were really true or just one of those myths that gets repeated a lot. I was pretty sure that each snow flake starts with a particle of dust, but what exactly are these particles? Are they all helpful? Is it taking pollution out of the air and bringing it back to the soil? Maybe snow is nature’s air cleanup process? But if so, how would that impact my garden soil?
So today I did a little research on these questions, and it appears to me that yes, snow is nature’s air cleaning process, but snow has a better reputation than it deserves as a fertilizer.
Nitrogen is the main thing that snow is credited for adding to the soil. So I started there, and learned that while snow does indeed bring nitrogen down from the air, various sources said that snow contains only about 2 to 5 pounds of nitrogen per acre. Out of this amount, some of the nitrogen will go back to the air from the surface and some will run off when the snow melts, so only a part of that 2 to 5 pounds will soak into the soil. To put this into some context, UConn says tomatoes and other annual vegetables need about 150 lbs of nitrogen per acre to grow well. So, the snow is adding such a tiny amount of nitrogen that it is barely worth mentioning, much less celebrating.
Sulfur dioxide was listed by the EPA online as a potential problem that can fall in snow as well as rain. I think most are already aware of the harms of acid rain, but could there by some benefit as well? My recent soil sample reports showed there are 8 ppm of sulfur in my garden, which is far less than the desirable range of 75 ppm according to the Bionutrient Food Association. Evidently rain and snow contain far less than 1 ppm of sulfur so that wasn’t giving any benefit to my garden worth celebrating either.
My research on other pollutants in snow (black carbon, benzene, toluene, ethylbenzene, etc.) became overly time-consuming and I did not find much information relevant to gardening other than recommendations not to eat it.
The one thing that is clear to me at this point is that soil microbes are essential for managing any excess pollutants and any beneficial trace elements, as well as the nitrogen (as little as it is), so it pretty much comes back to having a healthy soil filled with a diverse food web. At least snow does act as an insulating layer, like mulch, which protects the soil food web below. I came away from this whole thought process re-focused on prioritizing my plans of establishing perennial nitrogen-fixing cover crops throughout the garden this Spring.
Have you spent time thinking about the dust particles that form snowflakes and their impacts on your garden? If so, what have you learned about this? If you have anything to add, or just want to share your own experience from the big snow storm, please post a comment below.