So your Hebe "Amy" or similar variety looks like a standing corpse, brown and wilted. People think of Halloween when they drive by and the crows are watching the plants with cautious curiosity. Is it time to remove the sickly plant and try again or should you let it ? Should the same cool variety go in it's place or should you think about something new all together? We are advising gardeners to wait, if you can.
Many plants we use here in the Pacific Northwest are drought tolerant for our relatively dry summers and are hardy to temperatures in the 20's or low 30's. A lot of these varieties are natives to climates like from New Zealand and Australia. So when unusual shifts in weather cause intense freezes lasting longer than a few days and then the snow falls and then the ice... issues arise.
Microclimates will be the final deciding factor. If they are in a wet situation and unprotected, they will more likely be set for the compost bin. There is also the possibility that the rootball is stillviable and that it may resprout from the base. If you have the patience to wait a year or two your plant may or may not survive well. But the reason we are suggesting that you wait before you cut, is that the plant may regenerate from lower on the stems. As the weather warms, you start to see new growth appear. This is a possibility, but as I look around at a few of these sickly shrubs, I am more and more convinced that they most are going to perish, but it's still advisable to wait a few more weeks.
In the end you could try to replant the same and hope we don't have more of this uncharacteristic, yearly deep freeze or it might be time to consider something new for the space. Other hebe varieties can be more tolerant of the cold such as Hebe "Mrs. Winder". City People's Designer, Anne Janisse also suggests that the grey varieties seem to hold up in the cold as well.