What Are Hardiness Zones?

If you’ve ever gone to a nursery or hard store looking for new plants to add to your yard, you’ve likely come across something called Hardiness Zones. All plants have a recommended zone range, which is a number between 1-13. Those number coordinate with the zones of each area of the country, which is assigned a zone number. The Hardiness zones are based on the average annual extreme minimum temperature during a 30-year period. The zone numbers help to guarantee that a plant can survive the average winter low temperatures in a given area.


The zone maps are tools that show were various permanent landscape plants can adapt. If you want a shrub, perennial, or tree to survive and grow year after year, the plant must tolerate year-round conditions in your area. This helps gardeners compare their own garden climate with the climate where a plant is known to grow well.


However, like all rules, these were meant to be broken. Just because a plant isn’t in your exact zone doesn’t mean you can try to grow it! It may require special care, or if it’s a seasonal plant, you can plant it just for the summer and enjoy its blooms!


For the state Maryland, we’re in a zone range of 5b-8a, depending on different areas of the state. View the interactive map here to determine what zone your home is in!