Because our winters are now milder, Calgary has been recently re-classified from a Plant Hardiness Zone 3a to a Zone 4, which means we will have even more choices for perennials and more bee-friendly plants. It is important to know your Hardiness Zone when purchasing perennials if you want them to last more than one summer! (The Plant Hardiness Zone is “based on the average annual minimum winter temperature,” and now divided into 13-degree – previously 10-degree zones. A Zone 1 perennial plant can survive in extremely cold winter temperatures. The new zones of 11 to 13 can survive in the heat. Many annuals from hardiness zones 5 and up can still be planted in Calgary’s summer months).
An article in Edmonton Journal by Gerald Filipski entitled “Do your part to help the bees” (July 3, 2013) published a useful “seasonal guide to attract those productive pollinators to your garden year round.” By 2016 we already have quite a few on this list as emphasized in bold.
Late spring to early summer: Chives / Clarkia / Clover / Dianthus / Larkspur / Lupine / Osteospermum / Pea / Poppy / Alyssum / Viola
Mid-season: Bachelor’s Button / Basil / Black-eyed Susan / Gaillardia / Asclepias / Calendula / Echinacea / Cosmos / Dill / Feverfew / Foxglove / Monarda / Portulaca / Squash, pumpkin / Thyme / Coreopsis / Yarrow / Verbena / Petunia / Nasturtium / Nicotiana / Snapdragon
Late season: Asters / Dahlia / Cleome / Marigold / Salvia / Scabiosa / Sunflower / Zinnia
Shrubs for a border: Honeysuckle / Dogwood / Mock orange / Roses
There are other plants in our zone, which is now Zone 4 not Zone 3, that can be included in future acquisitions.
One of my own garden favourites is the Veronica longifolia ‘Candied Candles’ from Epic Plants – a tall pink-flowered Veronica speedwell that blooms profusely from July into September. I created a YouTube account for the Parkdale Community Garden. This YouTube video shows some of the buzzing activity. I am looking for a source for this plant in Calgary.
See also this July 15, 2016 Metro article by Helen Pike entitled “Calgary beekeeping trend worrisome for native pollinators: Calgary’s bee population could be choked out by a surplus of backyard hives.”