The big elephant in the room is our long and cold Alberta winters, which now have the added problem of wild temperature swings, and this is actually harder on plants than sustained extreme cold. Calgary was traditionally the more challenging place to garden compared to Edmonton because of the Chinook winds, but we see similar winters in Edmonton now. I expected last winter to be a bit of a doozy because of the temperature dropping from above zero to -50C lows where I live in the span of a week, but I have been pleasantly surprised to have lost only a few plants, with many plants greatly outperforming my expectations. A number of plants frequently listed at zone 5 are doing exceptionally well in my zone 3b garden north of Edmonton. In fact, all the plants I did lose are zone 2 or 3! This just goes to show you that zone ratings are not written in stone and must be taken with a grain of salt (especially since they are just the opinion of whomever printed the tag or wrote the webpage). In our perennial department at Greenland, I make a real effort to put zone ratings on our signage that reflect the collective experience of myself, our staff, and our customers, and this often contradicts what is found on grower tags, which are usually printed in warmer climates where zone 4 or 5 are considered “extreme cold” trials, and the plants are in fact, unbeknownst to them, hardier than zone 4 or 5.

The reality is that plants can die for many reasons; they have limited lifespans, and they are subjected to some pretty harsh conditions here in Alberta. Perfectly hardy plants can die after a couple years or 30, even as their neighbors and less hardy plants continue to flourish. Nature claims lives unselectively and without prejudice or regard for our arbitrary zone ratings. Our yards contain many microclimates which we must identify through some educated guesses and some trial and error and figure out what grows well where. What can you do to help prevent winter death? Of course, don’t plant things that are completely out of zone and expect them to survive. But also, start by planting the right plant in the right location, with the right technique, and invest in your soil by adding plenty of organic matter to it. Also make sure plants are watered in well just before freeze-up. These steps give any plant the best chance of survival. For extra winter protection, perennials and shrubs can be mulched with bark or straw once the ground has frozen. Shrubs can be covered with an empty box used as a frame to hold the mulch around the plant. Burlap screens can be used to protect evergreens such as cedars that are susceptible to winter kill from cold winds and sun reflecting off the snow or siding. But the point I’m trying to drive across is that plants can and do die despite our best efforts (they are not immortal and should not be considered permanent unless they’re plastic), and the more plants you have, the more plants you will lose. Consider it an opportunity to try something different!