WHAT ARE PLANT HARDINESS ZONES?

[hlthe2b]

8. The one thing I finally learned (and most newcomers don't) about Colorado, is no matter how

many warm spring days in March, April, or early May, don't plant ANYTHING outdoors until at least mid-May (and even then you may be covering well into June).

It seems every year many get tempted with all the plant displays at the nurseries and big-box stores, but I've finally been burned once too often. Yup, Zone 5, but spring makes us as iffy as a Zone 4.