The USDA, or the United States Department of Agriculture, provides a Plant Hardiness Zone Map. It is the standard by 
which gardeners and growers determine which plants are most likely to thrive at a certain location. The planting and growing season in Zone 6 ranges from mid-March (after the last frost) through mid-November, which is considerably lengthy. Most of Ohio falls in zone 6; the majority of Northeast Ohio is in Zone 6a. (This means the coldest the area gets is between -5 and -10 degrees Fahrenheit.) So what exactly does that mean to a Northeast Ohio gardener? To get a more accurate breakdown, we recommend you visit the USDA website —http://planthardiness.ars.usda.gov/PHZMWeb/ or check out this article which was published shortly after the hardiness zone map was updated by the USDA — http://www.cleveland.com/insideout/index.ssf/2012/02/what_new_hardiness_zone_means.html.
So what perennials are suited for Zone 6? Gardeners and growers need to be aware that the weather in this area can abruptly change, which all of us are accustomed to – it can be 80 degrees and drop to 40 degrees the very next day! Only in Cleveland, right!?! Despite the temperature swings, it’s actually a very favorable environment – a long growing season complimented by generally mild temperatures.
For a through list of flowers, fruits, vegetables, trees and shrubs that thrive in our hardiness zone, please review the information on this site: http://garden.lovetoknow.com/wiki/Gardening_Zone_6. You’ll quickly see that we have an assortment of perennials to choose from, keeping our gardeners and growers busy all year long!
