What do we mean here by global plant hardiness zones?
Quite simply it is a way to show how different areas in different countries would be rated under the USDA plant hardiness zone rating systems.
When gardeners talk about whether a plant will “survive” in their garden, they’re often referring to hardiness—a plant’s ability to withstand the cold temperatures of their region.
For decades, American gardeners have relied on the USDA Plant Hardiness Zone Map as their guide, but what about gardeners in the UK, Australia, or Germany? How do their growing conditions translate to this universal standard?
In this comprehensive guide, I’ve compiled equivalent USDA hardiness zone ratings for regions across nine countries: the United Kingdom, Canada, Australia, New Zealand, Germany, Netherlands, France, Belgium, and India.
Whether you’re relocating internationally, ordering plants from overseas catalogs, or simply trying to make sense of gardening advice from different parts of the world, these conversion tables will help you navigate the global language of plant hardiness.
For example, you can use these equivalents to to take advantage of comprehensive vegetable gardening guides and calendars, which are organised by US and UK hardiness zones.
What Are USDA Hardiness Zones?
The USDA Plant Hardiness Zone system divides regions into zones based on their average annual minimum winter temperature.
Each zone differs by 10°F, with sub-zones ‘a’ and ‘b’ representing 5°F increments. For example, Zone 8a experiences minimum temperatures between 15-20°F (-9.4 to -6.7°C), while Zone 8b ranges from 20-25°F (-6.7 to -3.9°C).
When a plant catalog or label says “Hardy to Zone 7,” this means the plant can typically survive winter temperatures as low as 0-10°F (-17.8 to -12.2°C). Knowing your zone helps you select plants with the best chance of surviving your winter conditions.
Global Plant Hardiness Zones: How to Use These Tables
- Find your region in the country-specific tables below.
- Note the equivalent USDA zone listed for your region.
- Use this zone information when selecting plants, particularly those with hardiness ratings from other countries.
- Remember that microclimates matter – urban areas, coastal regions, or sheltered spots may be slightly warmer than the broader region.
- Consider other factors – while hardiness zones focus on winter cold, your garden’s success also depends on summer heat, rainfall, soil type, and sunlight.
These tables serve as a starting point—a translation tool for gardeners to communicate across borders. With this knowledge, you can more confidently explore the world of plants, knowing how to interpret hardiness information regardless of its country of origin.
Lets start with the detail of the relevant temperatures in each of the USDA Hardiness Zones
USDA Plant Hardiness Zones: Average Annual Minimum Winter Temperatures
Here are the average annual minimum winter temperatures for each USDA hardiness zone, including the sub-zones (a, b):
| USDA Zone | Temperature Range (°F) | Temperature Range (°C) |
|---|---|---|
| 0a | -65 to -60°F | -53.9 to -51.1°C |
| 0b | -60 to -55°F | -51.1 to -48.3°C |
| 1a | -55 to -50°F | -48.3 to -45.6°C |
| 1b | -50 to -45°F | -45.6 to -42.8°C |
| 2a | -45 to -40°F | -42.8 to -40.0°C |
| 2b | -40 to -35°F | -40.0 to -37.2°C |
| 3a | -35 to -30°F | -37.2 to -34.4°C |
| 3b | -30 to -25°F | -34.4 to -31.7°C |
| 4a | -25 to -20°F | -31.7 to -28.9°C |
| 4b | -20 to -15°F | -28.9 to -26.1°C |
| 5a | -15 to -10°F | -26.1 to -23.3°C |
| 5b | -10 to -5°F | -23.3 to -20.6°C |
| 6a | -5 to 0°F | -20.6 to -17.8°C |
| 6b | 0 to 5°F | -17.8 to -15.0°C |
| 7a | 5 to 10°F | -15.0 to -12.2°C |
| 7b | 10 to 15°F | -12.2 to -9.4°C |
| 8a | 15 to 20°F | -9.4 to -6.7°C |
| 8b | 20 to 25°F | -6.7 to -3.9°C |
| 9a | 25 to 30°F | -3.9 to -1.1°C |
| 9b | 30 to 35°F | -1.1 to 1.7°C |
| 10a | 35 to 40°F | 1.7 to 4.4°C |
| 10b | 40 to 45°F | 4.4 to 7.2°C |
| 11a | 45 to 50°F | 7.2 to 10.0°C |
| 11b | 50 to 55°F | 10.0 to 12.8°C |
| 12a | 55 to 60°F | 12.8 to 15.6°C |
| 12b | 60 to 65°F | 15.6 to 18.3°C |
| 13a | 65 to 70°F | 18.3 to 21.1°C |
| 13b | 70 to 75°F | 21.1 to 23.9°C |
These temperatures represent the average annual minimum winter temperatures that define each zone, which is a key factor in determining plant survival during cold weather.
Global Plant Hardiness Zones: USDA Plant Hardiness Zone Equivalents by Country
Here are the zone equivalents for the various regions in the featured country
United Kingdom
| UK Region | USDA Zone Equivalent |
|---|---|
| Northern Scotland | 7a-7b |
| Southern Scotland | 8a-8b |
| Northern England | 8a-8b |
| Midlands | 8b |
| Southern England | 8b-9a |
| South Coast | 9a-9b |
| Cornwall/Scilly Isles | 9b-10a |
| London (urban heat island) | 9a-9b |
Canada
| Canadian Region | USDA Zone Equivalent |
|---|---|
| Southern British Columbia Coast | 8a-9a |
| Vancouver Island | 8a-9a |
| Southern Ontario | 5a-6b |
| Ottawa/Montreal | 5a-5b |
| Maritime Provinces | 5b-6b |
| Southern Alberta/Saskatchewan | 3a-4b |
| Northern Prairie Provinces | 2a-3b |
| Northern Territories | 0a-2b |
| Arctic regions | 1a-0a |
Australia
| Australian Region | USDA Zone Equivalent |
|---|---|
| Far North Queensland | 12a-13b |
| Northern Territory (Darwin) | 12b-13b |
| Northern Western Australia | 12a-13a |
| Northern Queensland | 11a-12b |
| Central Queensland | 10a-11b |
| Southeast Queensland | 9b-10b |
| Coastal New South Wales | 9a-10a |
| Sydney | 10a-10b |
| Southern Victoria | 8b-9b |
| Melbourne | 9a-9b |
| Tasmania | 8a-9a |
| Adelaide | 9b-10a |
| Perth | 9b-10b |
| Southwest WA | 9a-10a |
| Central Australia | 9b-11b |
New Zealand
| New Zealand Region | USDA Zone Equivalent |
|---|---|
| Northland | 9b-10a |
| Auckland | 9b-10a |
| Bay of Plenty | 9a-9b |
| East Coast | 9a-9b |
| Wellington | 9a-9b |
| West Coast (North Island) | 9a-9b |
| Nelson/Marlborough | 8b-9a |
| West Coast (South Island) | 8a-8b |
| Canterbury | 8a-8b |
| Otago | 7b-8a |
| Southland | 7a-7b |
| Central Otago (inland) | 7a-7b |
| Southern Alps | 6a-7a |
Germany
| German Region | USDA Zone Equivalent |
|---|---|
| North Sea Coast | 8a-8b |
| Baltic Coast | 7b-8a |
| North German Plain | 7a-7b |
| Central Uplands | 6b-7a |
| Rhine Valley | 7b-8a |
| Bavaria/Munich | 6b-7a |
| Alpine Foothills | 6a-6b |
| German Alps | 5a-6a |
Netherlands
| Netherlands Region | USDA Zone Equivalent |
|---|---|
| Coastal Areas | 8a-8b |
| Northern Provinces | 7b-8a |
| Central Netherlands | 8a |
| Southern Netherlands | 8a-8b |
| Urban Areas (Amsterdam, Rotterdam) | 8b |
France
| French Region | USDA Zone Equivalent |
|---|---|
| Northern France | 8a-8b |
| Paris Basin | 8a-8b |
| Brittany | 8b-9a |
| Atlantic Coast | 8b-9a |
| Central France | 7b-8b |
| Eastern France/Alsace | 7a-7b |
| Rhône Valley | 8a-8b |
| Mediterranean Coast | 9a-10a |
| Provence | 8b-9b |
| Corsica | 9a-10a |
| French Alps | 5a-7b |
| Pyrenees | 6a-8a |
Belgium
| Belgian Region | USDA Zone Equivalent |
|---|---|
| Coastal Flanders | 8a-8b |
| Central Belgium | 7b-8a |
| Ardennes | 7a-7b |
| Brussels (urban heat island) | 8a |
India
| Indian Region | USDA Zone Equivalent |
|---|---|
| Western Himalayas | 5a-9a |
| Eastern Himalayas | 7a-10b |
| Indo-Gangetic Plains | 10a-11a |
| Central India | 10b-11b |
| Western India/Gujarat | 11a-11b |
| Deccan Plateau | 10a-11a |
| West Coast (Mumbai, Goa) | 11b-12a |
| Southern India (Kerala, Tamil Nadu) | 12a-13a |
| Northeast India | 9b-11b |
| Andaman & Nicobar Islands | 13a-13b |
Note: These equivalents are approximations as microclimates, elevation changes, and urban heat islands can create significant local variations in all regions.
Martin Cole has been an avid plant lover and gardener for more than 20 years and loves to talk and write about gardening. In 2006 he was a finalist in the BBC Gardener of the Year competition. He is a member of the National dahlia Society.
He previously lived in London and Sydney, Australia, where he took a diploma course in Horticultural studies and is now based in North Berwick in Scotland. He founded GardeningStepbyStep.com in 2012. The website is aimed at everybody who loves plants or has been bitten by the gardening bug and wants to know more.
Gardening Step by Step has been cited by Thompson and Morgan, the UK’s largest mail order plant retailer, as a website that publishes expert gardening content.