Jessica Damiano's award-winning garden blog gets to the root of things.
Snowstorm coming -- which de-icer is best?
Forecasters are predicting another foot of snow will hit Long Island, starting tomorrow. I still haven't recovered from the last hit. Though my walkways and streets are all clear, there are snow mounds several feet high all over the yard. They were partly formed from natural snow drifts that occurred during the post-Christmas Snowpocalypse and partly from the deliberate dumping of shoveled snow, which reminds me: While you're out there shoveling the mess later this week, dump the snow from your driveway and walkways into your perennial beds, as long as you haven't salted the area. It will keep the soil temperature from fluctuating and protect against heaving (the lifting of bulbs and root crowns).
And if you really want to de-ice, do so after clearing walkways, and stay away from sodium chloride. It's the cheapest rock salt available, but it's the worst for your plants and the environment. If you must salt, use calcium chloride, but be aware that while it's safer, it still isn't ideal. You'll see it marketed at "pet safe" because it isn't as harsh as sodium chloride, but it still can cause irritation to pets' paws, so be sure to rinse them off and wipe them down if they've walked over it.
Want the greenest option? The one that's best for pets, plants and the groundwater? Stick to kitty litter. It won't melt ice, but it will provide some traction to reduce slipping.
And if the snow piles up on evergreen trees, like arborvitaes, as it did the last time around, be sure to bring a long-handled broom out there when you shovel, and use it to gently knock snow from branches. Otherwise, the weight of the snow will lead to buckled, misshapen, sagging branches that may never recover. Some might even break.