Snow and ice are less damaging to your soil than the salt used to melt it. (Brandy Baker / The Detroit News)
Thanks to the fluctuation in temperatures this winter, lots of ice has formed on my front walk, so I've had to use a lot of chemicals to melt it. And those that work best in bitter cold contain a calcium chloride and salt blend. That means the plants growing between the stones that make up my walkway are going to need some special care this spring.
Salt buildup in the soil will suck the water from the roots of plants, so even if there is moisture in the soil, the plants can die. Salts can also burn the tender microscopic root hairs that take up the moisture for the plant, which also results in damage and death.
One way to mitigate the problem is to flush the soil with 2 inches of fresh water a couple of times a week for a couple of months.
In an article about minimizing flood damage in the February issue of Fine Gardening, Jeff Gillman, garden author and associate professor of horticulture at the University of Minnesota, also recommends applying gypsum to the soil that binds up salts so you can flush them away.
Peter Schneider, renowned rosarian and author of the award-winning book "Right Rose, Right Place" (Storey), uses gypsum to flush the salt residue from chemical fertilizers that builds up in the soil in this rose garden. He applies it to the soil at a rate of 3 pounds per 100 square feet every other year. I don't use chemical fertilizers in my garden, so I don't have to worry about that issue.
According to Linda Chalker-Scott, an extension horticulturist and associate professor at Washington State University, gypsum can increase the leaching of iron, manganese and magnesium in some soils. It may also have negative effects on mycorrhizal fungi, so overuse can cause problems.
Many gardening books recommend the use of gypsum to break up clay soils; however it only works on certain kinds of clay, and that is not the type found here in Michigan.
If you're planning to use gypsum as a soil amendment, it's a good idea to get a soil test first and request recommendations on the use and amount, as they will vary depending on the type of soil in your landscape and garden.
Gypsum comes in both a pelleted and powdered form. The pelleted form is easier to work with. In either case, it's wise to wear a mask when working with it.
Nancy Szerlag is a master gardener and Metro Detroit freelance writer. Her column appears Fridays in Homestyle. To ask her a question, go to Yardener.com and click on Ask Nancy. You can also read her previous columns at detroitnewscom/homestyle.