USDA Plant Hardiness Zone Map

The success of your edible or ornamental garden largely depends on understanding your USDA plant growing zone. The USDA Plant Hardiness Zone Map helps you identify the most appropriate plants to grow in a particular area.

This zone map incorporates all regions in the United States and provides temperature and other details a plant needs to survive. Use this comprehensive article as a guide to know the right region to grow your plants.

What is the USDA Hardiness Zone Map?

The United States Department of Agriculture can be shortened as USDA. The organization released the first map of planting zones in North America in 1960 and has gone on to release updated editions detailing temperature changes around different regions.

The USDA plant hardiness zones are the regions your plants will survive. Most nurseries and seed dealers usually include the hardiness of plants on their product descriptions for buyers to know the USDA zone that best suits their plants.

Gardeners use the USDA planting zones to plan their plant selection process. They consider the microclimate of a region before planting. A microclimate is the section of a place where the climate is somewhat different from the average temperature of the place. For instance, the south-facing wing of your house in North America will be warmer than other sections. You can leverage this piece of information when planting.

How to Use the USDA Plant Hardiness Zone Map

The USDA Hardiness Zone Map indicates a particular region’s average winter temperatures by dividing the eastern areas of America into 10 degrees Fahrenheit zones.

You can access the USDA plant hardiness zone map on the internet. You can also find a particular hardiness zone by inputting the ZIP Code of that specific region in Google.

Some plants cannot survive cold water temperatures, while others can. With the USDA Zone Map, you can know the specific region your shrubs, trees, and perennials can survive. For example, if you want to grow a hardy plant in Zone 9, but you live in Zone 3, the chance of the plant surviving is slim. Instead, you can grow another plant that is suitable for your region.

While the USDA Plant Hardiness Zone Map can be very useful, it also has some limitations. For one, the zone map does not consider the benefits of snow cover on perennials plants. The USDA map also does not take soil drainage in cold temperatures and freeze-thaw cycles into consideration.

What You Can Plant in the Different Hardiness Zones

It is important you know what you can plant in a particular hardiness zone, so you do not end up with dead plants after putting all of your energy and time into growing them. Below is the USDA Plant Hardiness Zones and what you can grow in them.

Zone 1

Zone 1 temperature is below – 50°F, and just a few cities in Alaska are in this zone. Plants in this zone can tolerate the harshest weather conditions.

Plants you can grow in Zone 1 include Quaking Aspen, Netleaf Willow, Crowberry, and Pennsylvania Cinquefoil.

If you live in Zone 1, you should plant during mid-June.

Zone 2

Zone 2 temperature is between -50 and -40°F during the winter. Areas in Alaska such as Unalakleet, Pinecreek, and Prudhoe Bay fall into this hardiness zone. The best time to plant in Zone 2 is mid-June.

Common plants that thrive in Zone 2 include Bush Cinquefoil, Silverberry, Bunchberry, and American Cranberry bush.

Zone 3

This zone has a temperature range of -40 to -30°F during the winter. The northern parts of Dakota, Wisconsin, Maine, and Montana are in Zone 3. The ideal time to plant in Zone 3 is in mid-May.

Plants you will usually find in this hardiness zone include Smooth hydrangea, Siberian Crabapple, Woodfern, American Arborvitae, and Common Juniper.

Zone 4

The temperature range of Zone 4 is -30 to -20°F. Places in this zone include South Dakota, North Dakota, Wisconsin, Wyoming, Maine, New Hampshire, and Northern New York. Mid May is the best time of the year to plant in Zone 4.

Some common plants you will find in Zone 4 include Vanhouffe Spirea, Chinese Juniper, Sugar Maple, and Panicle Hydrangea.

Zone 5

During the winter, the temperature of Zone 5 is usually between -20 and -10°F. Northern-eastern and Midwestern states such as New York, Wisconsin, Michigan, Illinois, Nebraska, and Indiana fall in this hardiness category.

For your plants to thrive in Zone 5, plant them around mid-April.

You can grow some plants in Zone 5, including Slender Deutzia, Sycamore tree, Boston Ivy, Flowering Dogwood, and Japanese Yew.

Zone 6

Plants in Zone 6 can tolerate a temperature of about -10 to 0°F. States like Oregon, Washington, Kansas, Ohio, Illinois, and Missouri fall under this hardiness zone. The ideal time for growing plants in this zone is mid-April.

In Zone 6, you can grow hardy plants such as American Holly, Weeping Willow, Coralbells, and Common Boxwood.

Zone 7

During the winter, Zone 7 temperature can get range from 0 to 10°F. States such as Oklahoma, North Carolina, Virginia, and some parts of Oregon and Washington are in this category. Your plants have a higher possibility of surviving in Zone 7 if you plant them around mid-April.

Plants that thrive in Zone 7 include Texas rock rose, Bigleaf Maple, Magnolia tree, Kurume Azalea, Atlas Cedar, and English Holly.

Zone 8

Plants in Zone 8 prefer cooler temperatures ranging from 10 to 20°F. The growing season in this hardiness zone is longer than in the zones mentioned above. Places such as Georgia, North and South Carolina, Mississippi, Louisiana, and Alabama are in this category.
The best time to plant in Zone 8 is in mid-March.

You can grow plants such as Cherry-laurel, New Zealand Daisy-bush, Strawberry tree, Japanese Pittosporum, Texas mountain Laurel, and Laurustinus.

Zone 9

Plants in Zone 9 need a little more warmth and survive at a temperature of about 20 to 30°F. Places such as California, Florida, and Louisiana are in this hardiness zone.

If you are in Zone 9, the best time to plant is mid-February.

Examples of plants that bloom in Zone 9 include the California Pepper tree, Asparagus Fern, Australian bush cherry, Tasmanian blue gum, and Silk-oak.

Zone 10

Plants in Zone 10 can withstand hot temperatures that go as much as 30 to 40°F. Southern parts of Florida and California fall in this category.

For your plants to grow successfully, you need to plant them around mid-January.

Examples of plants that survive in Zone 10 include Violet Churcu, Golden shower, Royal Palm, Palmetto Palm tree, Lemon Eucalyptus.

Zone 11

The temperature of Zone 11 is about 40 to 50°F, and only tropical plants such as Lime, Grevillea, and Sago palm in Hawaii can survive under such temperature. Frost does not affect Zone 11, so you can plant anytime you want.

Guideline, Not a Strict Rule

Take the USDA Plant Hardiness Zone Map Information as a rule of thumb for planting and not a strict rule. If you understand how the hardiness zone map works and follow the guidelines, your plants will survive and thrive.