This is really helpful!
I find 34 plants on the list that I grow in a zone 4a garden which have proved hardy, and numerous others which lasted for a couple of seasons and then died.
A number of them are notably slower to increase and flower: Cortina for example, I've had for many, many years never blooming or growing. I'd decided that it'd be going in the compost pile this year but, amazingly it bloomed and really began growing! I've never heard that threatening mayhem would motivate plants, but it may have worked in this instance!
Jane Trimmer, Pagan Ritual, Better By Design, Beyond Riches, and Boundless Beauty are just a few from the list that truly excel here!
The winter weather has been milder here over much of the past 10 years, but cooling in the last 2 winters: lows of -30F both of the last two years, but no -40 (or worse). (Fun fact: -40 is the same in Celsius or Fahrenheit - damn cold!)
Thanks again for creating this wonderful resource- you've saved me a bundle!
