What growing zone are we and why does it matter?
How do you know which plants are hardy for our area and which will need extra care?
The first thing you will need to know is which zone we are. Government of Canada has an interactive map online. Canada's Plant Hardiness Site.
For our region, we are zone 3. This means any trees, shrubs and perennials labelled as zone 3 or lower will be tough enough to handle our climate without a lot of extra care and attention.I’ve included a couple of other links that are also important to understand:
- Alberta plant zone hardiness map https://www.plantmaps.com/interactive-alberta-plant-zone-hardiness-map.php
- Alberta last frost day map https://www.plantmaps.com/interactive-alberta-last-frost-date-map.php
- Alberta first frost date map https://www.plantmaps.com/interactive-alberta-first-frost-date-map.php
There are many benefits to understanding why these date are so important to ensuring your success as a grower. We will dive a little deeper into these maps and what they mean for you.
Alberta Last Frost Date - this is the expected last frost date of the winter. We use this date to determine when we can reasonably expect to plant outdoors. We will also use this date to determine the timing of any indoor seeding. For example, our last frost date is approximately May 20th. Therefore, if you are starting seeds indoors that require a seeding date of 6-8 weeks before last frost, you would seed them late March-early April. This will ensure they are the optimum size, not too big and not too small, for transplanting outdoors around May 20th.
Alberta First Frost Date - this is the expected first frost date in the fall. This date is important to understand especially when looking at vegetable or cut flower crops. All vegetable and cut flower seeds have a days to maturity. Most of the published days to maturity are from transplant date not seeding date. If you choose a vegetable with a long maturity time, the growing season may not be long enough for the cut flower or vegetable to mature. Our first frost day is approximately September 11th. With these dates our approximate frost free days is 114.
Of course, this is an estimate and will vary from year to year.