Hi Worthwhile,

I'm no expert, but I'll tell you what I've learned from my experience. Don't worry about covering them. I've done it every year (8 years now). Mine have never suffered from being completely covered up. It's colder where I live though, and mine aren't protected enough with just winter protection (they suffer - die - without snow cover and frigid temps).
Good luck,
Cassiope

If you're in a part of Ohio where you get reliable snow cover through most of winter, that is good. But covering Erica and Calluna with evergreens, as you did, is good practice. Not so much for protection from frigid temps, but as a screen. Once the ground freezes, it becomes difficult for roots to take up water, and plants are subject to dessication from sun and wind. This is why Erica and Calluna, in harsh climates such as yours (and mine), can show a lot of brown come Spring. (Last year was bad all over the east, even in milder Cape Cod, z7). I keep mine covered until early-mid April. If I happen to shear earlier, I recover them, because only the roots are in active growth once the ground thaws; foliage growth, for me, does not begin until mid-late May.

A greater problem for you might be the species you planted. E. darleyensis is rated hardy only to zone 7 (maybe zone 6 with protection). However, E. carnea, which also blooms late winter-early spring, is hardy in zone 5.