Gardening Hardiness Zones around the World

As a gardener, you sometimes plant crops that fail to grow or thrive despite giving them all the attention and care you can. These garden crops often fail to thrive because they are in a gardening zone that doesn’t suit their growth.

Gardening Hardiness zones refer to areas suitable for the growth of certain crops based on the average winter temperature of the region. Understanding hardiness zones is essential to determine which plants will grow well in your area and when to plant them.

This blog post will help you to understand what gardening Hardiness zones are. You will also know what determines and influences a hardiness zone. Also, you’ll understand what hardiness zones apply to your area, whether in North America, Europe, Asia, Australia, and Africa.

What are Gardening Hardiness Zones?

Gardening hardiness zones are regions classified based on the average minimum winter temperature, which helps determine the suitability of plants in a particular area. It uses the temperature of different regions in a country to determine the best crops you can grow in your garden. Therefore, the hardiness zones in a country differ, although some areas are similar and can successfully grow the same garden crops.

The United States Department of Agriculture (USDA) created the first hardiness zone map in 1960, and it is currently the most widely used standard for gardening hardiness zones. The map divides the United States into 13 hardiness zones based on a 10°F difference in the average minimum temperature of each zone.

Factors that Influence Hardiness Zones

Several factors influence hardiness zones, such as altitude, latitude, ocean currents, and topography.

Altitude

Altitude refers to the height of an area above sea level. Areas located near large bodies of water tend to have milder winters because water has a high heat capacity, which helps regulate temperature. On the other hand, areas located at high altitudes experience harsher winters because the air is thinner and less able to retain heat.

Latitude

Latitude refers to the position of an area with regard to the equator. Generally, areas closer to the equator have warmer climates than those closer to the poles. This is because the sun’s rays are more direct near the equator, which results in higher temperatures.

Topography

Topography can also influence hardiness zones. Areas with mountainous terrain can experience more extreme temperature changes than areas with flat terrain because of variations in elevation.

How Hardiness Zones Are Determined

To determine hardiness zones, the USDA uses a complex algorithm that considers several factors, such as the average minimum temperature, maximum temperature, and duration of cold weather in a particular area. The data is collected from weather stations across the country and analyzed to determine the average minimum temperature of each area.

The USDA also updates the hardiness zone map periodically to reflect changes in climate patterns. For instance, in 2012, the USDA updated the hardiness zone map to reflect the warming trend observed in recent years, which resulted in a shift of several hardiness zones northward.

Gardening Hardiness Zones in North America

North America comprises Canada, the United States of America, Mexico, Haiti, the Dominican Republic, Greenland, Jamaica, Puerto Rico, and many other countries. Some countries, such as Cuba and Puerto Rico, have similar climates. However, Canada and the United States of America differ from them climatically.

North America gardening zone

Regardless, the United States Department of Agriculture (USDA) developed the hardiness zone map, dividing North America into 13 zones based on average annual minimum temperatures.

The zones range from 1a (coldest) to 13b (warmest) and are determined by an area’s average annual minimum temperature. The colder zones are found in the northern regions of Canada and the United States, while the warmer zones are located in the southern areas, the Caribbean countries. Therefore, a plant suitable for Zone 8 may not survive in Zone 4 because of the colder temperatures.

Other than the USDA hardiness zone map, there are also Canadian hardiness zone maps, which are similar to the USDA map but take into account factors such as snow cover and wind chill.

Examples of Garden Crops that Thrive in Different Hardiness Zones in North America

Different plants thrive in different zones, depending on their tolerance for cold and heat. Here are some examples of garden crops that thrive in some of the hardiness zones in North America:

Zone 3

This zone is the coldest, with an average minimum temperature of -40°F to -30°F. Plants that can thrive in this zone include the Canada anemone, creeping phlox, and Siberian iris. You can plant these vegetables in Zone 3:

  • Kale
  • Swiss Chard
  • Lettuce
  • Tomatoes
  • Spinach
  • Cucumbers
  • Carrots
  • Radishes

Zone 5

This zone has an average minimum temperature of -20°F to -10°F. Plants that can thrive in this zone include the black-eyed Susan, coreopsis, and sedum. In this zone, you can grow vegetables such as:

  • Lettuce
  • Celery
  • Asparagus
  • Carrots
  • Cabbage
  • Cucumbers
  • Spinach
  • Turnips
  • Swiss Chards

Zone 7

This zone has an average minimum temperature of 0°F to 10°F. Plants that can thrive in this zone include the crape myrtle, lantana, and verbena. Garden vegetables that will thrive in this zone include:

  • Broccoli
  • Beets
  • Collards
  • Carrots
  • Cabbage
  • Potatoes
  • Peas
  • Spinach
  • Turnip
  • Onions
  • Lettuce
  • Kale

Zone 9

This zone has an average minimum temperature of 20°F to 30°F. Plants that can thrive in this zone include the bougainvillea, citrus trees, and oleander. In Zone 9, you can grow vegetables such as:

  • Cauliflower
  • Beets
  • Carrots
  • Brocolli
  • Cabbage
  • Brussel Sprouts
  • Turnips
  • Potatoes
  • Peas

Zone 11

This is the warmest zone, with an average minimum temperature above 40°F. Plants that can thrive in this zone include the banana tree, hibiscus, and plumeria. Gardeners in this zone can grow vegetables such as:

  • Tomatoes
  • Peppers
  • Strawberries
  • Cucumbers
  • Collards
  • Corn
  • Radishes
  • Asparagus

It’s important to note that these are just a few examples of plants that can thrive in these zones, and many other plants can also grow in these regions. It’s always a good idea to research the specific plant you’re interested in and its hardiness zone requirements before planting it. Check out the appropriate vegetables for zone 10.

Gardening Hardiness Zones in Europe

The gardening zone system in Europe is based on the same principle and is a helpful tool for selecting plants that can thrive in different climatic conditions across the continent. In general, the hardiness zones in Europe range from Zone 1 to Zone 10, with Zone 1 being the coldest and Zone 10 being the warmest.

Northern and central Europe typically fall into zones 4 to 8, characterized by cold winters and mild summers. Countries such as Sweden, Norway, Finland, and the Baltic States fall into zone 3 or lower, while countries such as Germany, France, and the United Kingdom are generally in zones 6 to 8.

Gardening hardiness zones in Europe

On the other hand, Southern Europe tends to fall into zones 8 to 10, characterized by mild winters and hot summers. Countries such as Spain, Portugal, Italy, Greece, and parts of France fall into these zones.

Examples of Garden Crops that Thrive in Different Hardiness Zones in Europe

In the different gardening zones in Europe, you’ll find that some vegetables thrive in the same zones across the countries.

Zone 3

This zone includes the coldest parts of Europe, such as northern Scandinavia, and is characterized by freezing temperatures in winter. Plants that thrive in this zone include arctic willow (Salix arctica), which is a small shrub that can survive in temperatures as low as -50°C, and the hardy Siberian iris (Iris sibirica), which can tolerate freezing temperatures.

Zone 5

This zone includes parts of northern and central Europe, such as the United Kingdom, Belgium, and the Netherlands. Plants that thrive in this zone include the lovely English bluebell (Hyacinthoides non-scripta), which produces blue-violet flowers in spring, and the colorful peony (Paeonia lactiflora), which blooms in shades of pink, white, and red.

Zone 7

This zone includes much of southern Europe, such as Italy, Greece, and Portugal. Plants that thrive in this zone include the fragrant lavender (Lavandula angustifolia), which is widely used in perfumes and aromatherapy, and the popular olive tree (Olea europaea), which produces delicious olives and is a symbol of the Mediterranean region.

Zone 9

This zone includes the warmest parts of Europe, such as southern Spain and the Mediterranean islands. Plants that thrive in this zone include the exotic pomegranate tree (Punica granatum), which produces juicy, tart-sweet fruits and has been cultivated for thousands of years, and the colorful bougainvillea (Bougainvillea spp.), which is a popular ornamental vine that produces vibrant pink, red, and purple bracts.

Gardening Hardiness Zones in Asia

In Asia, hardiness zones vary widely due to the continent’s vast size and diverse topography, which includes mountain ranges, deserts, and tropical rainforests.

In general, the northern regions of Asia have colder climates, while the southern regions are more tropical. For example, Siberia, in Russia’s far east, is known for its frigid temperatures and is classified as a hardiness zone 2a, meaning that the average annual minimum temperature ranges from -45 to -40 degrees Fahrenheit (-42 to -40 degrees Celsius). On the other hand, areas in southern Asia, such as Thailand, are classified as hardiness zone 11a, where the average annual minimum temperature ranges from 40 to 45 degrees Fahrenheit (4 to 7 degrees Celsius).

gardening hardiness zones in Asia

The Himalayan mountain range, which spans several countries, including India, Nepal, and Bhutan, is home to many climates and hardiness zones. For example, the city of Leh, in the Indian state of Jammu and Kashmir, is located in a high-altitude desert region and is classified as a hardiness zone 8a, where the average annual minimum temperature ranges from 10 to 15 degrees Fahrenheit (-9 to -12 degrees Celsius). In contrast, the city of Darjeeling, located at the foot of the Himalayas in West Bengal, India, has a more temperate climate and is classified as a hardiness zone 10b, where the average annual minimum temperature ranges from 35 to 40 degrees Fahrenheit (2 to 4 degrees Celsius).

In Southeast Asia, countries such as Indonesia, Malaysia, and the Philippines are classified as tropical climates, with hardiness zones ranging from 11a to 13a, where the average annual minimum temperature ranges from 50 to 70 degrees Fahrenheit (10 to 21 degrees Celsius).

Examples of Garden Crops that Thrive in Different Hardiness Zones in Asia

Asia is a continent with a vast range of climatic zones and landscapes, from Southeast Asia’s tropical forests to Siberia’s cold deserts. The hardiness zones in Asia vary from Zone 1 in the northernmost regions to Zone 13 in the southernmost regions. Here are some examples of plants that thrive in different hardiness zones in Asia:

Zone 1

In the coldest regions of Asia, where the temperature can drop as low as -50°F, only a few hardy plants can survive. One such plant is the Siberian dwarf pine (Pinus pumila), which grows to a height of only a few feet and can withstand extreme cold.

Zone 5

In the cooler regions of Asia, such as Japan and northern China, plants like the Japanese maple (Acer palmatum) thrive. These trees have delicate, lacy leaves that turn bright red in the fall and prefer a cool and humid environment.

Zone 9

In the temperate regions of Asia, which include parts of China, Korea, and Japan, plants like the camellia (Camellia japonica) and the Japanese cherry blossom (Prunus serrulata) are common. Both of these plants prefer a mild climate and bloom in the spring.

Zone 11

In the subtropical regions of Asia, such as southern China, Taiwan, and the Philippines, plants like the bougainvillea (Bougainvillea spp.) and the hibiscus (Hibiscus rosa-sinensis) thrive. These plants prefer a warm and humid climate and are known for their vibrant colors.

Zone 13

In the tropical regions of Asia, which include Southeast Asia and parts of India, plants like the banana (Musa spp.) and the coconut palm (Cocos nucifera) are common. These plants require a hot and humid climate and are known for their edible fruits.

Overall, Asia has many plants that can thrive in different hardiness zones, from hardy conifers in the far north to lush tropical plants in the south.

Gardening Hardiness Zones in Australia

In Australia, the Australian Bureau of Meteorology (BOM) has developed a system of hardiness zones for Australia based on the Köppen climate classification system. The system divides Australia into eight main zones with unique environmental conditions, including temperature, rainfall, humidity, and wind patterns.

Examples of Garden Crops that Thrive in Different Hardiness Zones in Australia

The eight hardiness zones in Australia are:

Alpine Zone

This zone covers the highest areas of the Australian Alps and has a cool, alpine climate with very low temperatures and high precipitation levels.

Vegetables you can grow in this zone include:

  • Beets
  • carrots
  • turnips
  • Kale
  • Lettuce
  • Spinach

Subtropical Zone

This zone is found in the northern coastal regions of Australia and has a humid subtropical climate with warm, wet summers and mild winters.

Some suitable vegetables for this climate include:

  • Corn
  • Cucumbers
  • Peppers
  • Squash
  • Zucchini

Tropical Zone

This zone covers most of the northern part of Australia and has a tropical climate with high temperatures, high humidity, and distinct wet and dry seasons.

Suitable garden vegetables for this climate include:

  • Okra
  • Sweet potato
  • Beans
  • Eggplant
  • Pumpkin

Desert Zone

This zone covers Australia’s central and western parts and has an arid desert climate with low rainfall, high temperatures, and low humidity.

Some suitable vegetables for this climate include:

  • Cactus
  • Peppers
  • Melons
  • Tomatoes

Mediterranean Zone

This zone is in southwestern Australia and has a Mediterranean climate with hot, dry summers and cool, wet winters.

Some suitable vegetables for this climate are the following:

  • Artichokes
  • Asparagus
  • Beets
  • Lettuce
  • Spinach

Temperate Zone

This zone covers the southern parts of Australia and has a temperate climate with mild, wet winters and warm, dry summers.

Grassland Zone

This zone covers eastern Australia and has a grassland climate with warm summers, mild winters, and moderate rainfall.

In this garden climate zone, you can grow vegetables such as:

  • Broccoli
  • Cauliflower
  • Cabbage
  • Carrots
  • Potatoes

Coastal Zone

This zone covers Australia’s eastern and southern coastlines and has a coastal climate with mild temperatures, moderate rainfall, and high humidity levels.

Some suitable vegetables for this garden hardiness zone include:

  • Brussels sprouts
  • Leeks
  • Onions
  • Peas
  • Radishes

Gardening Hardiness Zones in South America

South America is a large and diverse continent with a wide range of climatic conditions, and as a result, it is divided into several hardiness zones.

gardening hardiness zone in Australia

The hardiness zones in South America range from tropical to subpolar, with the tropical zones located near the equator and the subpolar zones in the southernmost part of the continent. The hardiness zones are determined based on the average minimum temperature in each region, with lower minimum temperatures indicating colder and more challenging growing conditions.

In general, South America’s northern and central regions have tropical and subtropical climates, with zones ranging from 8a to 12a on the USDA hardiness zone map. These regions have high temperatures and high humidity, with year-round rainfall in many areas. Plants that thrive in these zones include tropical fruits, such as mangoes and papayas, coffee, and cocoa.

The southern regions of South America have cooler climates, with zones ranging from 6a to 10a on the USDA hardiness zone map. These regions have cooler temperatures and lower humidity, with distinct seasons and less rainfall. Plants that thrive in these zones include temperate fruits, such as apples and pears, and cool-season vegetables, such as broccoli and lettuce.

Examples of Plants that Thrive in Different Hardiness Zones in South America

Here are some examples of plants that thrive in different hardiness zones in South America:

Hardiness Zone 8a

This zone is in southern Chile, where the climate is cool and humid. Some plants that thrive in this zone include:

Araucaria araucana, also known as the monkey puzzle tree, this evergreen conifer is native to Chile and Argentina. It can grow up to 50 meters tall and is a famous ornamental tree.

Nothofagus antarctica, commonly known as the southern beech, this tree is native to southern Chile and Argentina. It has a distinctive grey bark and can grow up to 25 meters tall.

Hardiness Zone 9a

This zone is along the coast of Peru and Ecuador, where the climate is warm and humid. Some plants that thrive in this zone include:

Bromeliads: These epiphytic plants are native to the tropical regions of South America and come in various colors and shapes. They are commonly used as ornamental plants and can be grown indoors or outdoors.

Heliconias: These tropical plants are native to South America and are known for their brightly colored flowers. They are often used in landscaping and can grow up to 3 meters tall.

Hardiness Zone 10a

This zone is in the Amazon rainforest, where the climate is hot and humid year-round. Some plants that thrive in this zone include:

Rubber trees: Native to the Amazon basin, rubber trees produce latex for making rubber. They can grow up to 30 meters tall and have large, glossy leaves.

Cocoa trees: Also known as cacao trees, these plants are native to the Amazon basin and are used to produce cocoa beans for making chocolate. They can grow up to 6 meters tall and have large, oval-shaped leaves.

Gardening Hardiness Zones in Africa

Africa, being a vast continent, has diverse hardiness zones.

gardening hardiness zones in africa
 

East Africa

The hardiness zones in East Africa range from 8a to 13a, with the higher zones being found in the highlands of Ethiopia and Kenya. The coastal regions of East Africa have a tropical climate, with slight variations in temperature throughout the year. The highlands have a more temperate climate, with cooler temperatures and more precipitation.

West Africa

West Africa is generally hot and humid, with hardiness zones ranging from 9a to 13b. The coastal regions have a tropical climate, while the inland regions have a more arid or semi-arid climate. The Sahel region, which stretches across West Africa, is characterized by a dry climate and is classified as a hardiness zone 11a.

Southern Africa

Southern Africa has a range of hardiness zones, from 8a to 13b. The coastal regions have a Mediterranean climate, with mild, wet winters and warm, dry summers. The inland areas have a more arid or semi-arid climate, with cooler temperatures in the highlands.

Northern Africa

Northern Africa is mostly desert or semi-desert, with hardiness zones ranging from 8a to 13b. The Mediterranean coast has a mild, wet winter and a hot, dry summer, while the Sahara desert has extreme temperatures and very little precipitation.

Central Africa

Central Africa has a tropical climate, with hardiness zones ranging from 9a to 13b. The region is characterized by high temperatures and high humidity, with heavy yearly rainfall. The Congo Basin, which covers much of Central Africa, has a very wet climate and is classified as a hardiness zone 13b.

Examples of Plants that Thrive in Different Hardiness Zones in Africa

Hardiness Zone 12 (Tropical Wet and Dry Climate)

This zone’s climate is hot and humid, with a distinct wet and dry season. Plants that thrive in this zone include:

  • African lily (Agapanthus africanus)
  • Bird of Paradise (Strelitzia reginae)
  • Hibiscus (Hibiscus rosa-sinensis)
  • Bougainvillea (Bougainvillea spp.)
  • Plumeria (Plumeria spp.)
  • tomatoes
  • peppers
  • cucumbers
  • beans

Hardiness Zone 11 (Tropical Savanna Climate)

This zone’s climate is hot, with wet and dry seasons. Plants that thrive in this zone include:

  • Baobab (Adansonia digitata)
  • Flame tree (Delonix regia)
  • Jacaranda (Jacaranda mimosifolia)
  • Marula (Sclerocarya birrea)
  • Neem (Azadirachta indica)
  • onions
  • garlic
  • carrots
  • lettuce
  • yams
  • cassava
  • plantains
  • taro

Hardiness Zone 10 (Subtropical Climate)

This zone’s climate is warm, with mild winters and hot summers. Plants that thrive in this zone include:

  • Aloe vera (Aloe vera)
  • Avocado (Persea americana)
  • Lemon (Citrus limon)
  • Mango (Mangifera indica)
  • Papaya (Carica papaya)
  • onions
  • garlic
  • carrots
  • lettuce

Hardiness Zone 9 (Mediterranean Climate)

This zone’s climate is mild, with wet winters and dry summers. Plants that thrive in this zone include:

  • Olive (Olea europaea)
  • Fuchsia (Fuchsia spp.)
  • Geranium (Pelargonium spp.)
  • Lavender (Lavandula spp.)
  • Rosemary (Rosmarinus officinalis)
  • Zucchini
  • Squash
  • Peppers
  • Tomatoes

Hardiness Zone 8 (Desert Climate)

In this zone, the climate is scorching and dry. Plants that thrive in this zone include:

  • Cactus (Opuntia spp.)
  • Date palm (Phoenix dactylifera)
  • Joshua tree (Yucca brevifolia)
  • Mesquite (Prosopis spp.)
  • Saguaro cactus (Carnegiea gigantea)
  • Okra
  • Eggplant
  • Cowpeas
  • Sweet potatoes

Final Thoughts

Wherever you are, your climate and seasons determine which garden crops you should grow. Garden crops that thrive in the cold climates may not survive the warmer climates. Therefore, before you plant any crop in your garden, ensure that it is adaptable to your locality’s environment.

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