It’s been a mild fall but in the near future, homeowners, businesses, and municipalities will be removing snow and ice from sidewalks, parking lots, and roadways. Owners and property managers know that snow removal is critical for safety reasons. There is, however, one more safety concern to take into account – the safety of our trees.
The Pittsburgh 2030 District, Western Pennsylvania Conservancy, Tree Pittsburgh, Pittsburgh Downtown Partnership, and Allegheny County Conservation District recently held a workshop on de-icers and trees, sharing some great information about the importance of trees and how to protect them from damage caused by ice melt products.
Why Care about Trees?
Let’s put some dollar amounts on it. According to Pittsburgh’s 2014 street tree inventory, the total annual benefits from our trees is about $2.24 million dollars. The increase is property value alone accounts for $1.55 million of those dollars. Want to know more about the value of the street tree near your home or office? Pittsburgh’s My Tree Keeper website lists the complete inventory of street trees and their annual benefits.
It takes 3-5 years for a street tree to become established. Sadly, the life expectancy of street trees is only an average of 8 years. Often they simply don’t survive due to problems during the establishment period. One of the problems they face most often? Salt.
What Does Salt do to the Soil?
- Creates an environment where nothing will grow
- Prohibits absorption of water and limits oxygen exchange
- Limits nutrient uptake by the plant
- Raises pH levels
- Damages beneficial fungi in the soils, which form a symbiotic relationship with tree roots
Not only does salt cause harm to trees from the bottom up, it also hurts them from the top down. Fine salt particles can be picked up by the wind and affect trees farther from the application site by damaging their buds.
Selecting an Alternative to Salt
Rather than using salt (also known as sodium chloride or NaCl) this winter, consider using one of these alternative de-icers:
- Calcium magnesium acetate (CMA) – This product is the most plant-friendly.
- Magnesium chloride
- Calcium chloride
- Potassium chloride
Make sure you carefully review the chemical content of the products you’re considering. A product could be marketed as “safer” because it contains 5% CMA and 95% NaCl – not much better than 100% NaCl.
Important note: if you’re using ice melt on your LEED® certified building, you’ll want to review Reference Guide Correction ID# 100002010 – The Site Management Policy section has special guidance for environmentally friendlier products.
Group buying is a great way to save money on de-icers. Owners and property managers often choose salt because it is generally the least expensive option. Purchasing in bulk and splitting the cost across several organizations can lower the cost of de-icer to pricing comparable to the retail cost of NaCl. Interested in group buying for your organization? Send us an email at firstname.lastname@example.org.
How to Apply and Remove De-icers
Once you’ve picked out your product, apply it as sparingly as possible. Using less product will also save you money.
- Remove as much snow/ice as you can before applying de-icer.
- Apply only a small amount – one teaspoon per square foot.
- Avoid spreading de-icer on green space areas and in tree pits.
- Collect unused de-icer once area is clear of snow/ice for later use.
- Use coarse sand to improve traction and make walkways less slick.
Lastly, after the tree buds begin to open, you’ll need to remove any excess salt from the soil around your trees. Flush the tree pits using 20-30 gallons of water and apply the water carefully to give the soil time to absorb it. Don’t wait for the spring rains – salt damage may already be done by that time.