Photo by: https://www.flickr.com/photos/stellastella/
Here in Edmonton, we’re never really sure when the winter will truly come to an end—but we know what it’ll leave behind. Salt damage is a perennial problem in our region. Thanks to the months of icy weather, compacted snow, and slippery roads we endure every winter, our city relies on salt-based de-icing products to keep everything running smoothly. As it turns out, all that salt is just as harmful to our landscapes as excessive table salt is to our blood pressure!
What is Salt Damage?
When you take a bite of a too-salty dish, chances are the first thing you reach for is a glass of water. Salt, or sodium chloride, is a desiccant—that means it tends to dry stuff out. On our roads, this is good news; the sodium dissolves the ice to bond with the water. However, in our landscapes, this drying effect can have disastrous consequences.
As cars drive through the salty Edmonton streets, they pick up traces of salt in their treads and spread more salt throughout the residential streets. Over time, this becomes a fine salt spray that enters the air and settles all over your landscape. If you use a salt-based de-icer to clear your driveway, walkways, or front steps, even more sodium enters your yard. As snow melts and re-freezes, the salty runoff spreads to your lawn, garden, and any other element of your landscape in its way. Over time, this leaves behind many a salt-damaged Edmonton landscape.
How to Identify Salt Damage in the Landscape
Salt damage looks a little different depending on where you find it. Your front yard is more likely to be damaged by salt due to its close proximity to the public roadway. Here’s what to look for to spot and diagnose salt damage.
Hardscaping: Large areas of poured cement are more prone to salt-related damage than interlocked pavers. Cracking and caved-in areas are common issues that occur when salt has caused the underlying ground moisture to thaw and freeze rapidly. Interlocking, salt-resistant pavers stand up much better to these conditions.
Perennials: As the salt dissolves into the soil, perennials are some of the first plants to suffer. Salt prevents water uptake as the plant struggles to recover in the spring. To make matters worse, the sodium ions make essential nutrients difficult for plants to access, which causes leaf burn and die-back early in the season. The results are plants that appear parched (even in the wet spring weather), stunted or weak growth, and reduced density of leaves and flowers.
Photo Credit: https://commons.wikimedia.org/wiki/File:Blueberry_nitrogen_burn.JPG
Wooden Decking: Salt may temporarily help with slick deck surfaces, but the long-term damage is not worth the fast fix. Too much sodium interferes with the natural moisture of the wood and can cause the decking to corrode and splinter prematurely. In severe cases, the wood can corrode beyond what a fresh sanding and coat of wood stain can repair. Weak, brittle wood can also become a safety hazard over time.
Trees: Some trees are pretty well-adapted to the average urban environment, but newer and more delicate trees are at risk of unsightly salt damage that isn’t easy to reverse. Evergreens, in particular, are prone to needle tip burn (browning of needles) and twig or stem dieback. Deciduous trees are prone to nutrient deficiencies resulting in reduced fruit production, premature fall colour or early leaf drop, stunted leaf or stem growth, and discoloured foliage. Trees weakened by sodium are also more prone to disease and pest infestation.
Shrubs: Shrubs, like perennials, can suffer a lot from an excess of sodium in the soil. Flowering and fruit-bearing shrubs may show salt damage with a delay in bud break, discoloured foliage, lack of fruit (or poor fruit quality), reduced vigour, and areas that appear “burnt” or brittle, particularly on the side that faces the source of the salt.
Fixing Salt Damage
Once salt damage is done, it’s hard to reverse during the same season. If you’re concerned about the sodium content in your soil, you can attempt to counteract the effects by watering your plants early and often to flush salts away. Amend the soil with compost and gypsum to restore balance to the area. Prune salt-damaged areas of your plants as soon as you can to help them divert resources to healthy growth. Check your hardscapes for salt damage early in the season and call us if you notice any signs of damage that concern you.
Salt Damage Prevention
It’s much easier to prevent salt-related damage in the landscape than to fix it.
Protect your landscape by:
- Installing a barrier to protect vulnerable plants: Mulch, landscape fabric, burlap or plastic covers are excellent for shielding plants and soil.
- Using a non-sodium de-icer: There are non-sodium alternatives you can use to de-ice your property than aren’t as damaging to plants, such as calcium chloride, magnesium chloride, potassium chloride, and calcium magnesium acetate. While these products are more expensive than salt, you can make them go further by combining them with some sand, gravel, or sawdust to improve traction.
- Lining walkways with salt-resistant plants and features: Building margins of river rock or planting salt-resistant plants around your walkways helps to contain the damage proactively.
Salt-Resistant Landscape Plants
Living in an urban environment makes it nearly impossible to avoid salt altogether. If you find yourself replacing dried-out plants year after year, choosing the right plants for your conditions is a springtime game-changer. These plants are tough enough to put up with salty conditions.
- Paper Birch
- Northern Red Oak
- Bur Oak
- Hybrid Elms
- Sedum Autumn Joy
- Blanket Flower
- Butterfly Weed
- Juniper (multiple varieties)
- Tatarian honeysuckle
- Mugo pine
- Staghorn sumac
- Japanese spirea
- Rugosa rose
- Reed Grass “Karl Foerster”
With our harsh Edmonton winters, de-icing salt is one of those “can’t live with it, can’t live without it” kind of things—we all need to put up with it to some extent. Salt damage is a hassle to deal with, but if you know how it works, it’s possible to keep it at bay. If you believe a plant or element in your landscape may have salt damage, contact our team for an assessment. We can help you take your landscape from salty, to sweet!