From the wet winters of the Pacific Northwest to the extreme heat of the Southwest, there is no doubt that growing conditions in the United States and Canada are incredibly different. Luckily, we have gardening guides to give gardeners quick reference as to whether or not we can grow a plant in our garden and expect it to survive. Here’s how to utilize garden areas and end your frustration over yet another dead plant.
Gardening zones are mentioned all the time in gardening guides. You’ve probably read them on your seed packets and when I talk about plants I’m currently obsessed with.
They have become a huge indicator in modern gardening. Help us determine which plants will grow best based on where we live.
But with the changing gardening spheres, they are not as modern and helpful as they used to be.
Today, I want to explain to you how you can use gardening zones to plan plants in your garden and when to take zones with a grain of salt.
This post will cover…
What are the gardening zones?
Horticultural zones, also known as plant hardiness zones, usually refer to either the Canadian or American system. Determining which plants can grow in certain temperatures, It is represented as a number from 0-13, with subfields labeled “A” or “B”. For example, Vancouver is considered zone 7-8.
Different parts of the world will use different indicators, but hardiness zones are what I usually refer to on Garden Therapy because they are fairly common in North America.
In the American system, they base garden zones on minimum annual temperatures. The higher the zone number, the warmer the winters and the higher the minimum temperatures during the year.
Gardening areas in Canada are comparable but other variables are also taken into account Like rain and frost dates. This is a little more detailed than the American system, but it still begs the question, Will the plant survive the lowest temperatures of the year?
Gardening zones are a basic indicator of whether a plant will grow in your area, but it Does not take into account other environmental considerations Such as type of soil or amount of sunlight.
For example, Vancouver and parts of Texas share the same area. One is temperate rainforest, while the other is subtropical and humid. Definitely not the same!
How to use your garden area
So, how do you use zone numbers and apply it to your garden? You’ll find the zone range on seed packets, plant tags and referenced online, and it helps determine whether your plant is considered a perennial in your area.
The garden zone number will tell you whether the plant is hardy enough to survive the winter and come back the following year.
For example, a daylily grows in zones 3-10. That’s a pretty good range! If your garden is in this zone, your daylilies will grow well and be perennial. If you live outside of this zone, daylilies can be difficult to care for, and they will only grow as annuals.
If a plant is planted in a suitable area, it will have better chances of survival. Native species are especially great to purchase because they are already determined to grow well in your environment.
It is also important to keep in mind Many plants in Canada will have USDA hardiness zones on their labels. Instead of Canadians. Although they are similar, they are still not the same. For example, USDA zone 4 is equivalent to zone 5 in Canada. So keep an eye out!
What zone am I in?
Before buying flowers, shrubs, and, let’s say, more plants at the garden center than you came there for, it is important to know the growth zone of your garden.
In Canada, zone numbers range from 0-9. Zero is the coldest climate, where winters drop below -45°C, while nine is the warmest, where winters range from 7 to -1°C. To pinpoint exactly what your region and subregion are, refer to The Canadian Government Plant Hardiness Map is here,
In the United States, their gardening zones range from 1-13. One is the coldest climate, with winter lows ranging from -60 to -55°F, and Thirteen is the warmest, with winter lows ranging from 65 to 70°F. To find the area in your area, refer to USDA plant hardiness zone map here,
I also highly recommend you Connect with local gardeners in your area. Talk to your local nursery for plant suggestions based on what will thrive in your growing conditions.
A local gardening chapter will also have gardening experts who can tell you more about your specific areas for gardening and microclimates.
Microclimates and changing horticultural zones
As I mentioned above, there’s more to finding out than just your zone and what plants will thrive in your garden. Garden zones take minimal consideration of conditions such as rainfall, peak summer heat, frost duration, maturity timelines and more.
Each garden will have its own microclimate. So, when I live in Vancouver, I can drive twenty minutes and experience very different weather. The coast is cooler than the valley, where temperatures can be 5°C warmer.
Could be in your own backyard Different microclimates. One side of the house may have more sunlight while the other side may be exposed to stronger winds. With time and attention, you can observe the conditions in your garden and better understand the needs of your plants.
The field of gardening is also changing. We used to rely on thirty-year averages to determine minimum temperatures, frost dates, precipitation, and more, but climate change is drastically altering these averages. The situation of the 90s is not like today.
In BC, increased wildfires mean my plants are under more stress and produce more at different times. Or drought conditions mean our plants are not getting as much rain during the summer as they used to.
All this to say you have to keep this in mind Horticulture sectors do not have perfect indicators and are actively changing themselves. When in doubt, consult horticulturists and master gardeners in your area to better understand your local conditions.
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