Don't Forget Your Plants When Choosing a De-Icer
After a slapstick-style fall on our icy driveway last week, I am fortunate to have my bones intact. That pratfall, which would have made Jerry Lewis proud, reminded me that how we melt ice is important to the safety of people, pets and plants.
Shovels or snow blowers will open the way, but it takes some variety of salt, used with a traction agent such as sand or gravel, to keep pedestrians upright.
There are various salts used as ice-melting materials. The mineral dissolves in snow and ice, lowering the freezing temperature of water. The brine, or salty liquid, keeps walks and driveways from freezing at night and during snow or ice storms.
Exposure to or digestion of some of these compounds can be harmful to children and pets. Check warnings on bags.
These chemicals might also be bad for plant health as runoff washes salts into adjacent planting beds and also into our rivers and streams.
Keep them at least 20 feet away from salt-sensitive woody plants. Those include azaleas, crab apples, crape myrtles, dogwoods, forsythias, American hollies, maples, red maples, rhododendrons, sweet gums, white oaks, white pines and yews.
Some salt-tolerant woody plants are bald cypresses (Taxodium), hawthorns (Crataegus), hedge maples (Acer campestre), Siberian pea shrubs (Caragana arborescens), green ashes (Fraxinus pennsylvanica), honeylocusts (Gleditsia triacanthos var. inermis), sycamores (Plantanus) and junipers. Most woody plants and perennials are fairly tolerant of ice-melting salts that haven't been applied in large amounts.
Irrigation and aeration, completed with a plug aerator and some compost in spring, will help salt pass through soil. If there isn't a lot of rain in late winter and early spring, irrigate beds heavily affected by these chemicals with about six inches of water in spring.
Here's a closer look at some available salts:
· Sodium chloride, in the form of rock salt, is the most common melting agent. Of all salts, this one hurts plants most. It will cause soil to hold water so tightly that plant roots aren't able to absorb it. Extremely high salt content can kill plants by pulling water from them, a process called exosmosis.
Ascertain salt sensitivity when acquiring plants, and don't shovel snow from salted sidewalks onto plants.