GREEN THOUGHTS: Making salt sweeter

WE’RE ALL AWARE that Albany politics can be salty, and recently the city’s mayor made headlines with brine. According to Mayor Sheehan, using liquid brine, instead of rock salt crystals to treat icy roads and sidewalks, can save money and is better for the environment. Using brine might also be a smart political strategy, since leadership careers have been made or destroyed by government’s response to winter storms. Plants, too, care about how streets are cleared, because ice melters splash on foliage and soak into soil. I hear brine and think of pickles, so how can it be used to win the votes of street trees, sidewalk shrubs and citizens alike?

First, consider that salt harms plants in several ways. When your salt shaker clogs up in the summertime, it is because the salt has absorbed atmospheric moisture. Salt in the soil does the same thing, binding with clay and causing it to swell and become more compacted. Compacted soils offer less air and water, poorer drainage, and reduced rooting space to plants. As a result, plants can actually experience drought stress even when there appears to be moisture in the ground.

Secondly, salt is composed of sodium ions and chloride ions. Plants can absorb large quantities of chloride ions through their roots, faster than a dieter can inhale potato chips in a late-night binge. The chloride ions travel to the leaf and shoot tips, causing “marginal scorch,” which is a fancy way to say the edges of the leaves turn brown. On deciduous trees, this may not show up until spring, but on a white pine, the needle tips turn brown by late winter. The sodium ions are no kinder; they can block the plant’s uptake of magnesium and potassium, causing a deficit of these nutrients

Lastly, if salt is splashed directly on foliage and twigs, it can enter the cells directly and make the plant less cold tolerant. All this makes salt damaged plants less vigorous and more prone to insect or disease attack. Often, the greatest injury is on the side of the plant facing the road.

While throwing down rock salt to melt ice is simple, using liquid brine is a bit brainier. Applied to roads before a storm as a pre-treatment, brine doesn’t let snow stick, which makes snowplowing easier and faster, and reduces the total amount of salt needed to make travel safe. Brine is made by creating a solution of 23% rock salt and 77% water. So while salt is still used, the amount needed is decreased. And interestingly, pickle brine, beet and grape juices, beer waste and cheese water are all additives that may work to make the rock salt more effective and the solution a bit friendlier.

Better than brine is calcium magnesium acetate, which contains no chlorine and completely biodegrades. Unfortunately, it normally carries a high price tag, so calcium chloride might be more affordable. While it does contain chloride, it is more effective than rock salt, so less is needed. Good news for trees.

David Chinery is the horticulture educator for Cornell Cooperative Extension of Rensselaer County. Reach him at

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