Twenty-seven years ago I planted my first perennials, shrubs, and trees around the Ohio home where I currently live. The natural soil is heavy, poorly draining clay that is almost impossible to dig into, so I have added a lot of organic matter to the perennial beds. We have summer temperatures up to 105 and winter temperatures of -25. Years with little rain, and years with lots of rain. This area was once considered zone 5, but the latest update now has it as zone 6. I've grown many perennials through the years. Many grew one or two seasons and then never appeared again. Some were plagued with insect or disease problems that I didn't want to deal with. A few had no problem surviving - I had a problem with them spreading or setting seed that grew everywhere.