Learning about plant hardiness zones is crucial if you want to have a thriving landscape.
Have you ever heard gardeners talking about their “growing zone” and wondered what they were talking about? Or have you noticed the “plant hardiness zones” listed on trees and shrubs at your local nursery? Familiarizing yourself with information is crucial if you want to have a thriving landscape.
This guide tells you everything you need to know about finding your zone and using information about your zone’s growing conditions for your garden’s benefit.
What is the plant hardiness zone map?
The USDA plant hardiness map is a useful tool for gardeners and farmers to determine which plants will thrive in their region. The map divides the United States into 11 different growing zones based on the average annual minimum winter temperature. Each zone represents a 10°F temperature range, from the coldest (Zone 1) to the warmest (Zone 11).
The hardiness map is important because it provides a consistent system for farmers and gardeners across the United States to share information and make informed decisions about which plants to grow. Minimum winter temperature is a critical factor in determining which plants will survive in a given area. That’s because plants not adapted to the cold temperatures in a particular zone may not survive the winter, while plants that are well-suited to the climate will thrive.
Why is knowing your growing zone important?
Knowing your USDA plant hardiness zone is essential because it can help you select plants that are suitable for your climate, ensuring that they will succeed in your garden. If you plant a species that is not adapted to your zone, it may not survive the winter, or it may not produce fruit, flowers, or foliage as well as it would in a zone that is better suited to its needs.
How to find your USDA plant hardiness zone?
The map above shows the 11 plant hardiness zones in the USA. Check the color of your location against the map legend to see what zone you live in. This corresponds to growing zones listed on plants at your local nursery.
For a closer look at your growing zone, see our regional maps below.
North Central US
Includes: Bismarck (4a); Saint Paul (4b); Des Moines (5a/b); Jefferson City (6a)
The North Central USA is characterized by a continental climate, with cold winters and hot summers. With a diverse landscape that includes grasslands, forests, and lakes, gardeners in the region will find fertile soils for growing many different fruits and vegetables. Since the region is prone to severe weather, including droughts, it’s important to choose plants that can withstand changing conditions.
Includes: Montpelier (4b); Concord (5b); Indianapolis (6a); Charleston (6b); Richmond (7b)
The North Eastern USA is made up of coastal areas, forests, and mountains providing a humid continental climate with warm summers and cold winters. Home gardeners in this region have plenty of planting options, with many crops thriving in the region’s fertile soils and moderate temperatures. Vegetables like tomatoes, lettuce, and cucumbers, as well as fruits like apples, pears, and strawberries, all do well here.
Includes: Miles City (3b); Helena (4b); Cheyenne (5b); Spokane (6b); Boise (7a); Seattle (8b)
The Northwestern USA encompasses a diverse landscape that varies depending on location. In coastal regions, the climate is generally mild and rainy, perfect for a wide variety of fruits and vegetables. Inland regions are drier and experience greater temperature fluctuations, but still offer many opportunities for home growing. The overall region is particularly well-suited for growing fruits like apples, pears, and berries, as well as vegetables like tomatoes, lettuce, and squash.
South Central US
Includes: Oklahoma City (6b); Little Rock (8a); Austin (8b); Houston (9a)
The South Central USA is characterized by a subtropical climate with hot, humid summers and mild winters. The landscape of this region is varied, with rolling hills, forests, and river valleys dotting the scenery. Home gardeners in this region have a long growing season, with the ability to plant crops year-round. Vegetables like tomatoes, peppers, and okra, as well as fruits like peaches and plums, thrive in the warm, humid climate.
Includes: Nashville (7a); Raleigh (7b); Montgomery (8a); Tallahassee (8b); Tampa (9b); Miami (10b)
The South Eastern USA growing zone is known for its hot and humid climate with mild winters. The landscape features coastal plains, rolling hills, and lush forests offering a long growing season. Gardeners can produce a wide variety of crops, including tomatoes, peppers, and squash, as well as peaches, strawberries, and blueberries.
Includes: Salt Lake City (6b-7b); Albuquerque (7a/b); Las Vegas (9a); Sacramento (9a/b); Los Angeles (9a-10b)
While the desert climate of the South Western USA might not be a gardener’s first choice, the hot dry summers and mild winters do offer some opportunities. The landscape of this region is dominated by vast deserts, rugged mountains, and canyons, providing unique challenges in the way of extreme climate and soil conditions. But the area’s mild temperatures can still accommodate a variety of crops with proper planning and care. Drought-resistant vegetables like peppers, tomatoes, and eggplants, as well as fruits like figs and pomegranates, are well-suited to the South Western USA.
What can I do with this information?
Knowing what zone you’re in is important for a number of reasons. Not only will this knowledge help you choose the right plants for your garden, it will also help you care for them throughout the year. Read on for more tips on using information about your growing zone.
Choose plants based on your growing zone
Check the plant tags or seed packets for the plants you want to grow. They will usually indicate which zones the plants are suited for. If you’re not sure what plants will do well in your zone, consult with a local nursery or extension service for guidance. They can recommend plants that are well-suited to your region and provide tips on how to care for them.
Plan your garden
By using the hardiness zone map, you can plan your garden more effectively. You can group plants with similar hardiness ranges together to ensure they will thrive in the same conditions. This is especially important if your property features microclimates (see below).
Time your plantings
The hardiness zone map can help you determine the best time to plant certain crops. If you live in a colder zone, you may need to start your seeds indoors, in a greenhouse, or plant them later in the season to avoid frost damage.
The map can also help you identify microclimates in your yard. A microclimate is a small area that has different growing conditions than the surrounding area. For example, a sheltered area next to a south-facing wall may be warmer than other parts of your yard, which may allow you to grow plants that are not normally suited to your zone. Using raised beds or cold frames to provide extra warmth and planting in sheltered areas to protect plants from harsh winds are two examples of how gardeners create microclimates.
Improve plant care
Understanding your hardiness zone can also help you care for your plants properly. You’ll know when to expect frost and can take steps to protect your plants, such as covering them with blankets or moving them indoors or into a cold frame or greenhouse.
Will my growing zone change over time?
Climate change is having a significant impact on plant hardiness zones and will continue to do so over time. As temperatures rise, the zones shift, which means that plants that were once suited to one zone may no longer be able to survive there. One study from the University of Iowa modeled how growing zone boundaries may shift north by 13.3 miles per decade between 2041 and 2070 under future warming scenarios. While this can expand the growing range for certain crops, it can also lead to a decline in plant diversity, changes in ecosystems, and challenges for farmers and gardeners.
It’s essential for gardeners and farmers to monitor changes in their local climate and adjust their planting and care strategies accordingly. This might include planting fruit trees with a shorter number of required chill hours or protecting heat intolerant crops from heat waves. By selecting plants that are better adapted to the changing climate, gardeners can help ensure the long-term health and productivity of their gardens while supporting the preservation of plant diversity.
Knowing your USDA plant hardiness zone is an essential step in creating a successful home garden. The map provides valuable information about which plants are best suited for your climate, helping you select plants that are more likely to thrive in your garden. By understanding your zone, you can also plan your garden more effectively, care for your plants, and take advantage of microclimates in your yard.
Whether you’re a seasoned gardener or a beginner, taking the time to find your USDA plant hardiness zone is a valuable investment that can save you time, money, and effort while creating a beautiful and productive garden.
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