We started July off with a bang. More like a volcanic explosion where the searing heatwave felt like burning embers embedded into our skin. What naturally follows an unprecedented heatwave? Wildfires.

As the wildfire smoke envelopes us like an unwelcome hug and kiss from Great Aunt Gladys; we attempt to go about our daily routines with the warnings of air quality issues and ways of reducing our exposure. This leads me to my question, if the air quality can harm human health, can it hurt our garden plants? Those poor green guys can’t lift up their roots and run inside; they are stuck out there in the smoky haze 24/7.

How Do Edmonton Wildfires Affect Garden Plants?

Environment Canada considers an air quality health index rating of 7-10 to be ‘high risk.’ Calgary decided to be the teacher’s pet with a rating of 10 on Sunday; this is forecasted to continue throughout most of the week. While we close up our windows (and embrace the use of our Covid masks) as we attempt to avoid the outdoor air, what is happening to our garden edibles, perennials, trees, and shrubs? Invent N-95 masks for plants? Here are a few more realistic steps to help out your smoky garden:

• Rinse and repeat. A good thorough watering and hosing down of all our outdoor plants is advised. Rinsing trees, shrubs, perennials, and vegetables will help clear away particles that are likely lingering on the foliage. We suggest you do this a few times over the course of the next week or two.
• Bring in tropicals and container plantings. Potted plants are thankfully portable and will be much happier if brought inside for the week.
• Harvest early. Those tomatoes that aren’t quite ripe or the cucumbers that are still slightly small””harvest them anyway. An early harvest is better than a smoke-scented cucumber. If you place your picked tomatoes by a sun-filled window, they will slowly ripen a bit more””or embrace a dinner of fried green tomatoes!
• Peel and wash. For the produce that you’re not willing to part from the garden just yet, consider peeling and thoroughly washing it when you do decide to harvest””even weeks later, the smoke may have cleared, but the remaining ash particles could still be lingering on the skin of your edibles.

In terms of your larger trees and shrubs, they should all be fine in the long term. The best thing you can do is rinse those leaves. The smoke particulate can build up on foliage, minimizing photosynthesis and blocking the stomata (the pores of the leaf that process CO2). 

A Positive Plant Side Effect to the Edmonton Smoky Air

There’s always a silver lining. Think of it this way””remember how you were so worried about the heat-stressed plants during the epic heatwave? Well, the cloudy, hazy skies are giving them a reprieve from the hot sun. And, if we can believe our weather forecasters, rain is arriving later this week. In the meantime, stay safe!