While de-icing salts are said to be essential to keep safe mobility for travel routes (e.g. roads, parking lots, sidewalks) their extensive use can become very harmful to wood species and landscapes near or around road sides where most often used. It is estimated that an average of 1.86 trees per km of highway in Canada are affected by salt and need to be replaced each year. Environment Canada completed a five year study of the effects of road salt on the environment. It was concluded that rock salts are toxic to the environment, particularly in large concentrations. Rock salt, consisting of 98.5% of sodium chloride (NaCl), is one of the cheapest and most commonly used for de-icing roads and pavement.
Salt damage through salt spray
Salt spray damage happens via airborne mostly on trees or plants near busy highways. Salt spray lands on a dormant twig and can enter the tissue through leaf scar. On Evergreen trees, salt damage is first noticeable when the needles show ‘tip-burn’. The tips of the needles firs turn yellow, then bronze and subsequently become brown and begin to drop prematurely. As the needles die, the photosynthetic capacity of the tree is curtailed. Over the years the amount of new growth is reduced, causing the tree to weaken, dieback and perhaps die. On deciduous trees the salt spray affects the opening of buds and twigs. Buds are slow to open or may fail to open as the chloride tends to accumulate in dormant twigs and buds. Entire branches may be bare as the spring & summer arrive.
Salt damage though soil
When Salt in the soil dissolves, it separates in to Sodium and Chloride Ions. These contribute differently to the damaging of the tree. Chloride Ions absorbed by the roots enter the sap, concentrate in the shoots and prevent buds from opening. Later they can be transported to actively growing leaf margins causing the leaf to scorch, curl and even die. Sodium Ions are taken through the same chemical route as the necessary tree nutrients go through and can tie up the plants shuttle system, restricting the uptake of magnesium and potassium, two essential chemicals for trees and plants. The roots there for can’t take in water through osmosis and begin to die of thirst.
Minimizing Salt Injury
With growing awareness on environmental concerns there are companies that contribute to finding environmentally friendly alternatives and solutions. One company in particular is leading the way with environmentally friendly ice melting products. XYNYTH Manufacturing Corp. offers two fantastic environmentally friendly products with potassium being their major component, Mountain Organic Natural™ Icemelter & GroundWorks Natural™ Icemelter benefit the environment as potassium is a mayor nutrient for plants and trees. While these products are very powerful and effective they are also safe around vegetation, children and pets.
Some people choose to use low-cost but toxic products like rock salt and calcium chloride; they may have to factor in the replacement costs of future plantings. Not to mention the damage done to the environment like trees and vegetation. There is a variety of product lines to choose from. However consumers must keep in mind that traditional icemelters are toxic, dangerous and damaging. One way to minimize salt injury to trees and plants is to start thinking green and making better healthier choices with the type of de-icing products we use.