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| Photo by Beckie Anderson |
Winter is here, along with the snow and ice we don’t have to worry about during the warmer months. Although the snow brings moisture that will help our plants flourish next spring, it does make getting around in the winter tricky and even dangerous at times. Ice melting products help clear away the slick surfaces, but with more products available every season it can be difficult to choose which is right for your situation.
The original ice melter is rock salt, sodium chloride. It's great because it's inexpensive, but it has drawbacks too. It can cause damage to exposed metals and excessive amounts can accumulate in the soil, causing high salinity that can interfere with plant growth. This is especially a concern in areas of clay soil since it is more difficult to leach build up from clay than from silt or sand. Sodium chloride is effective to 12 degrees Fahrenheit, so at lower temperatures, the snow that was once melted will re freeze into ice.
Calcium chloride is another common ice melter. It will melt ice to temperatures as low as -25 degrees F, but it often makes a slimy coating on hard surfaces such as concrete. Exchanging slick ice for slippery slime may not be much of an advantage. It can be damaging to plant roots if it is used in excess.
Urea is a fertilizer that is sometimes used to melt ice. It seems like a good idea to go with a fertilizer, since it will feed your plants as the snow melts. However, melted snow doesn't always end up on the lawn. Run off from urea treated areas that goes into storm drains will eventually find its way to streams and lakes. This can contribute to excessive accumulation of nitrates in the water supply.
Calcium magnesium acetate is a new generation of ice management that prevents snow partials from sticking to each other, rather than melting the snow into a brine as the salt products do. It is generally not harmful to concrete surfaces or plants. However, it is less effective when temperatures drop below 20 degrees. Depending on the year, this could be a drawback when we have one of those deep freezing winters.
With each product having pros and cons, is there anything that is actually safe and useful? All of these products can be used with little ill effect if the amount applied is kept minimal. The products are all more effective if the snow is shoveled first then ice melt applied. Problems will start cropping up if large amounts of product are poured on the ground and expected to take care of all the snow. Often the effects won't be evident until spring, when edging plants lack vigor and concrete damage shows up. I'm sorry I couldn't get you off the hook for snow shoveling duty, but using sparing amounts of an ice melter along with a little effort to remove the majority of the snow should help everyone have a safer winter season with fewer slips on the ice.