Southern Ontario Planting Zones: What Is My Growing Zone?
Are you a gardener in southern Ontario, eager to cultivate a thriving landscape but unsure where to start?
In this post, we'll talk about the Southern Ontario Planting Zones, your essential guide to understanding your region's climate and selecting the perfect plants for success.
If you'd like to learn more, click on a title to jump ahead:
If you're not sure where to get started with Southern Ontario planting zones, Gauld Nurseries is here to help. Our Niagara Region family-run centre has the expertise to assist with all our your gardening needs. Message us today!
1. What are Canadian Plant Hardiness Zones?
The Canadian Plant Hardiness Zone Map, much like its American counterpart, the USDA Planting Zone Map, divides the country into distinct zones based on average annual minimum temperatures.
Canadian Plant Hardiness Zones are a system used to classify different regions of Canada based on their average annual minimum temperatures. This classification helps gardeners and landscapers determine which plants are likely to survive and thrive in a specific area. The zones range from 0 to 9, with 0 being the coldest and 9 being the warmest. Each zone is further divided into two subzones (a and b) to account for slight temperature variations within the zone.
You can find the official Canadian Plant Hardiness Zone map on the Natural Resources Canada website: https://planthardiness.gc.ca/?m=1
This map is a valuable tool for anyone planning to plant trees, shrubs, or flowers in Canada. By knowing your plant hardiness zone, you can select plants that are well-suited to your local climate, increasing your chances of gardening success.
Southern Ontario Planting Zones consist of Zone A and B.
2. Southern Ontario Planting Zones
Ontario, Canada is a massive province. Southern Ontario is generally within planting zones 6a to 7b, depending on the specific location. Here's a breakdown:
Zone 6a: This zone covers the northern parts of Southern Ontario, with average minimum temperatures ranging from -23°C to -29°C (-10°F to -20°F).
Zone 6b: This zone is located in the central parts of Southern Ontario, with average minimum temperatures ranging from -20°C to -24°C (-4°F to -8°F).
Zone 7a: This zone covers the southern parts of Southern Ontario, with average minimum temperatures ranging from -18°C to -23°C (-0°F to -10°F).
Zone 7b: This zone is located in the southwestern parts of Southern Ontario, with average minimum temperatures ranging from -15°C to -18°C (5°F to 0°F).
Important Note: These are general zones, and specific locations within Southern Ontario can vary slightly. It's always best to consult a local gardening expert or use the Canadian Plant Hardiness Zone Map to determine the exact zone for your location.
Zone 6 is one of the Southern Ontario planting zones.
3. Southern Ontario Planting Zones: 6
Zone 6 in Southern Ontario encompasses areas with average minimum winter temperatures ranging from -20°C to -29°C (-4°F to -20°F). This zone includes parts of central and northern Southern Ontario, including cities like London, Kitchener-Waterloo, and Barrie.
It's important to note that within Zone 6, there are two subzones: 6a and 6b. Zone 6a is colder, while Zone 6b is slightly warmer.
Zone 6a is a specific climate zone within the broader category of Zone 6. It indicates a colder climate compared to Zone 6b.
Key characteristics of Zone 6a:
Average minimum winter temperature: -23°C to -29°C (-10°F to -20°F)
Location in Southern Ontario: Northern parts of Southern Ontario, including cities like Barrie, Orillia, and parts of the Greater Toronto Area.
Key characteristics of Zone 6b:
Average minimum winter temperature: -20°C to -24°C (-4°F to -8°F)
Location in Southern Ontario: Central parts of Southern Ontario, including cities like Kitchener-Waterloo, London, and parts of the Greater Toronto Area.
Just because you live in a more northern area, doesn’t mean you can’t have a beautiful garden!
Gardening in Zone 6:
While Zone 6a has a shorter growing season and colder winters, you can still create a beautiful garden with careful plant selection. Here are some tips for winter gardening:
Consider microclimates: Look for sheltered areas in your garden, such as south-facing slopes or areas near buildings, where plants may enjoy milder conditions.
Protect young plants: During harsh winters, consider providing extra protection for young trees and shrubs, such as wrapping them in burlap or using frost blankets.
Choose cold-hardy varieties: When selecting plants, opt for cultivars known for their cold tolerance.
Mulch: Apply a layer of mulch around plants to help insulate their roots and protect them from frost.
Plants That Thrive In Zone 6:
Here are some plants that thrive in Zone 6:
Trees:
The Oak is a tree suitable for a Zone 6 climate.
Deciduous:
Sugar Maple
Red Maple
Red Oak
Coniferous:
Colorado Blue Spruce
White Spruce
Balsam Fir
Shrubs:
Junipers, from the evergreen family, also thrive in Zone 6.
Flowering:
Hydrangea
Forsythia
Lilac
Evergreen:
Juniper
Yew
Boxwood
Perennials:
Flowering:
Daylilies
Black-eyed Susans
Hosta
Ornamental Grasses:
Miscanthus
Feather Reed Grass
Switch Grass
Remember: These are just a few suggestions. The best way to choose plants for your specific location is to consult with a local nursery or gardening expert. They can provide tailored advice based on your unique climate and soil conditions.
Zone 7a is a climate zone in Southern Ontario with a slightly milder winter than Zone 6.
4. Southern Ontario Planting Zones: 7
Zone 7 is a climate zone with an average minimum winter temperature ranging from -18°C to -12°C (0°F to 10°F).
In Southern Ontario, Zone 7 is further divided into two subzones:
Zone 7a: This zone has an average minimum winter temperature of -18°C to -23°C (0°F to -10°F). It covers the southern parts of Ontario, including cities like Toronto, Hamilton, and Niagara Falls.
Zone 7b: This zone has an average minimum winter temperature of -15°C to -18°C (5°F to 0°F). It covers the southwestern parts of Ontario, including cities like Windsor, Leamington, and parts of the Niagara Peninsula.
Key characteristics of Zone 7a:
Average minimum winter temperature: -18°C to -23°C (0°F to -10°F)
Location in Southern Ontario: Southern parts of Ontario, including cities like Toronto, Hamilton, and Niagara Falls.
Key characteristics of Zone 7b:
Zone 7b is the warmest zone in Southern Ontario, with the mildest winters.
Average minimum winter temperature: -15°C to -18°C (5°F to 0°F)
Location in Southern Ontario: Southwestern parts of Ontario, including cities like Windsor, Leamington, and parts of the Niagara Peninsula.
Gardening in Zone 7a and b:
Zone 7a offers a longer growing season and milder winters, allowing for a wider variety of plant choices. Here are some tips for gardening in this zone:
Take advantage of the longer growing season: Plant heat-loving vegetables and flowers earlier in the spring.
Protect tender plants: During late spring frosts, be prepared to cover tender plants to protect them from damage.
Choose heat-tolerant plants: Select plants that can withstand the summer heat and humidity.
Water wisely: During dry periods, provide adequate water to your plants, especially during the hot summer months.
By understanding the specific conditions of Zone 7 and following these tips, you can create a beautiful and productive garden
Plants That Thrive in Zone 7:
Here are some plants that thrive in Zone 7:
Trees:
The dogwood is a beautiful tree that thrives in Southern Ontario Planting Zones 7a and b.
Deciduous:
Dogwood
Sweetgum
Black Gum
Coniferous:
Eastern White Pine
Eastern Red Cedar
Bald Cypress
Shrubs:
The Christmas favourite, Holly, is commonly found in Southern Ontario Planting Zones 7a and b.
Flowering:
Azalea
Camellia
Hydrangea
Evergreen:
Boxwood
Holly
Yew
Perennials:
Flowering:
Coneflowers
Hosta
Peonies
Ornamental Grasses:
Miscanthus
Feather Reed Grass
Switch Grass
Remember: For the most accurate plant selection, it's recommended to consult with a local nursery or gardening expert. They can provide personalized advice based on your specific climate, soil conditions, and desired garden aesthetic.
By understanding the unique climate and soil conditions of the Southern Ontario planting zones, you can create a beautiful and thriving garden.
Whether you're a seasoned gardener or a beginner, armed with the knowledge of your specific zone, you can make informed decisions about plant selection and care.
Happy gardening!
Get Help With Southern Ontario Planting Zones From Gauld Nurseries
A family tradition since 1950, Gauld Nurseries offers a unique botanical experience nestled within the Niagara Escarpment Biosphere Reserve. Plus, our friendly and knowledgeable staff are on hand to answer any questions you find have about choosing the right plants for your zone.
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