Let’s face it, this winter could have been worse for us (poor Boston!) But for some evergreen shrubs it was bad enough to cause damage to leaves that normally get through the winter just fine.
For the most part, it was not a bad winter…except for a period of single-digit lows in February accompanied by days that did not get above freezing. Those lows came after a stretch of mild weather. If you’re an evergreen shrub, this can be a bad combination!
During periods of mild winter weather, dormant plants may begin to “soften” in preparation for spring regrowth. If temperatures plummet while plants are in this state, damage called “winter burn” can occur. This can look like varying degrees of leaf discoloration, even to the point of turning black.
While unattractive, this damage is usually confined to the outer- or topmost leaves and can be pruned out with minimal impact. Evergreen shrubs will usually shed damaged leaves and regrow fresh new ones in spring after suffering winter burn, even if you do not prune out the affected growth.
Although it can look severe, it is rare for a healthy hardy plant to be killed by brief periods of very cold temperatures. Once spring growth covers the damage, in most cases you will hardly be able to tell by summer that there was a problem.
Here's a loropetalum that had been winter-burned badly. Despite all the brown, dead leaves that had not been pruned, these are tons of healthy new pink leaves growing. The dead leaves will fall off and by June you'll hardly know what happened.
UPDATE: Same Loropetalum in May. Completely rebounded from the winter burn it had. The burned leaves were never pruned, most have fallen off on their own or been completely covered by new growth.