Ohio, like many other states, is comprised of several different hardiness zones. When it comes to gardening, the hardiness zone you live in is extremely important for the success or failure of your plant. A hardiness zone is a way to classify the climate of a particular area. These zones are important for gardening and farming because plants cannot grow if temperatures dip below or above a certain temperature.
In central Ohio, and on both the west and east side, there are small pockets of hardiness zone 5A. In the central region, this is around the areas of Knox and Richland. The very top of Ohio and most of the bottom half are mostly zone 6A. Zone 5B takes up most of Ohio but does not descend very far south in the state, but rather hovers around the top and middle of the state. At the very tip of Ohio is zone 6B.
When planting in a state like Ohio, where there are different zones bordering one another, it is important that you choose plants that are more cold-tolerant rather than take the risk of choosing a plant that cannot tolerate the temperature in your area. For example, if you live in zone 5 but closely border zone 6, you should first look for plants that would thrive in zone 5 before looking for plants that grow in zone 6.
For more information on the particular zone you live in, as well as a detailed map, there are a number of different websites that provide interactive maps. These maps will show you the zone in which you live, so that you can determine the plants that would have the best survival rate. Although frustrating when you can't grow particular plants because of the cold, recognizing and understanding hardiness zones can make a world of difference in your garden.