by Emma Murphy, Master Gardener (Twitter @Hey_MzEmma)
It’s an unfortunate reality. We live in Canada and we get snow, lots of snow. And then there’s the ice. So our industrious public works folks are out there putting down road salt (sodium chloride) and sand to keep us moving. We also apply salt or sand on paths and walkways on our property. Unfortunately it seeps into the soil and kills plant roots. Road salt mixed with melted snow creates a mist that blows on to our properties, especially when cars splash through melted snow. Having lost a few very nice plants to a combination of huge snowbanks and road salt, I was curious about what plants can survive (and maybe flourish) in a front garden that inevitably gets doused in road salt.
What Does Road Salt Do?
The negative effects of road salt on humans and the natural environment have been well documented. The Smithsonian magazine has two great articles on the subject.
The Hidden Dangers of Road Salt What Happens to All the Salt We Dump on the Roads?
Road salt doesn’t just dissolve into thin air. It splits into sodium and chloride ions and gets absorbed into roadside plants, licked up by wildlife or accumulates in aquatic ecosystems—sometimes with devastating consequences. All that saltiness can help invasive or even toxic species spread, not to mention increase traffic danger due to deer and moose drawn to salt-covered roads. (From a gardening perspective, if you want to deep dive into the nasty things that happen to soil structure from salts, this article by the Soil Science Society of America provides some great insight.)
What Perennials Can Handle Road Salt?
Our Savvy Gardening friend Tara Nolan (@ThatTaraNolan) (who you may remember as a speaker from our 2017 Peterborough Garden Show) recently posted a great blog post on how we can combat the road salt challenge in our gardens.
Salt-tolerant Plants that will Survive in Road Salt-laced Soil
So what are some of Tara’s favourites salt-resistant plants?
Autumn Joy Stonecrop (Sedum spectabile ‘Autumn Joy’)
Butterfly weed (Asclepias tuberosa)
Blanket Flower (Gaillardia)
Russian sage (Perovskia atriplicifolia)
‘Karl Foerster’ reed grass (Calmagrostis acutifolia ‘Karl Foerster’)
Silver mound Artemisia (Artemisia schmidtiana Silver Mound)
Some other ones I found doing an Internet search:
Rugosa roses (Rosa rugosa)
Lilacs (Syringa vulgaris)
Summersweet (Clethra alnifolia)
Lady’s Mantle (Alchemilla mollis)
So, if your garden is looking less than wonderful due to winter salt damage, try some of these options!