You Bet Your Garden

Melt your ice, not your plants (and watch your ash!)
By Mike McGrath

This time of year, I get a lot of questions about ecologically-friendly alternatives to the rock salt everyone throws down to melt ice.

This is good to ask. People who spread rock salt (or other sodium chloride formulations) on icy walkways risk harming nearby plants and making their soil so salty that nothing will grow there.

Luckily, a number of ice-melt products are made from calcium and/or potassium chloride (and sometimes magnesium). While the "chloride" (i.e. chlorine) isn't great for plants, calcium and potassium are essential plant nutrients, making them much better choices than products that contain sodium chloride.

Read the labels carefully. Sometimes sodium chloride (NaCl) is a hidden ingredient in what seems to be a salt-free melter. You can also use old-fashioned cinders or the "flame weeders" I'm always talking about. Several of these devices tout their ability as ice melters. Or, if you have a wood-burning stove, spread the ashes on the ice instead of throwing them away. Don't dump them on your garden! These ashes are very alkaline.

If your lawn or garden soil is too acidic, you can use the ashes instead of lime to raise your soil's pH. Have your soil tested, and then your local county extension agent (who will also set up the testing for you) can tell you exactly how much to use. Ashes are also high in "potash," an old term for potassium, which is the essential nutrient for getting lots of fruits and flowers.

However, ashes are very alkaline, and if you just toss them on a garden without first testing the soil, you could screw up the pH enough to harm or even kill some plants. Never use ashes around acid-loving plants like blueberries, evergreens, azaleas and rhododendrons.

You Bet Your Garden can be heard Saturdays at 11 a.m. on WHYY 91FM.

Information about the program and more of Mike's gardening tips can be found at You Bet Your Garden online.