Green Circle Growers Blog

Deicers Can Damage Garden Plants

Green Circle Growers - Tuesday, March 01, 2011

After spending the summer feeding, weeding and watering your garden, a bad winter can destroy those hours of hard work in an instant. It’s not usually the cold or snow that does in carefully-nurtured garden plants; it’s the application of rock salt and salt-based deicers on ice-slicked walkways and driveways that turns spring shoots brown and causes emerging plants to shrivel up and die.

As they scatter rock salt across icy sidewalks and down slippery stairs during the winter, few people consider the consequences of saturating garden beds with concentrated doses of salt. As melting ice soaks into lawns and garden beds, the salt transported in runoff can build to lethal levels. Salt build-up in the soil can damage delicate plant roots, causing emerging spring flowers to struggle and fail. The solution is to stop using rock salt despite its very low price and start using one of the environmentally-friendly “green” deicers.

Although more expensive, green deicers are as effective as rock salt and won’t harm garden plants or create environmentally-harmful runoff. To choose a garden-friendly deicer, check product labels and use the chemical information below as a guide:

  • Calcium magnesium acetate. Admirably biodegradable, calcium magnesium acetate has very low toxicity and won’t harm plants. Make products containing this chemical your first choice for garden safety.
  • Calcium chloride. Less toxic to plants than the following two products, calcium chloride comes in easy to scatter pellets and is often sold in convenient shaker containers.
  • Magnesium chloride. Deicers containing magnesium chloride are often mixed with agricultural byproducts from corn or grains. The fillers reduce the amount of chemical required for effectiveness, thus reducing the potential damage to garden plants. However, high concentrations of this chemical will kill plants so use sparingly or avoid its use if ice is a recurrent problem.
  • Sodium chloride. Stay away from deicers that list plant-killing sodium chloride (the chemical name for salt) as an ingredient.