In areas with cold winters, gardeners are always on the lookout for perennial plants that are reliably cold-tolerant in their gardening zone. Hardy plants are, by definition, those that survive in the ground, even where frost will penetrate deeply into the soil in the dead of winter. It is important for gardeners to know their hardiness zone. The lower the number of your zone the colder your winter is.
Recently, we are facing special challenges because of climate change and more variability in weather fluctuations. Your zone number may have been increased by one digit. Be cautious, however, as one thing that is predictable about climate change is that the weather is more unpredictable. Err on the side of caution and avoid buying plants that are unreliably hardy in your current zone.
Also, adhere to the rules about where to site new plants in your yard. For example, remember the south side of your garden will warm up earlier in the spring than the north side. Plants that do not thrive where the ground freezes and thaws a lot should not be planted with a southern exposure.
Azaleas and rhododendrons are best if given a northern exposure which does not encourage them to break dormancy too soon, as the ground stays cold longer. However, plant your earliest blooming daffodils, like the miniature tete-a-tetes, on the south side of your house, as they like to wake up very early each spring.