Everyone knows that Escallonia gets badly frostbitten. Every book says that Escallonia is a tender hedge plant. Every list of plants that "only grow in the south-west" (it used to be "in the Scillies") contains Escallonia. Every article says it should only be used as coastal hedging. I even read a piece in a reputable gardening magazine that suggested you cover your escallonia with horticultural fleece. So you would think that the recent freeze would have made your escallonia red raw with cold.
I'm going to argue with the books on this. We are in Somerset, it's true. All the same:
The temperature dropped to -11C this winter and there was plenty of windchill for long periods.
A 2.5 metre escallonia hedge near us, used as a windbreak, showed bronzing of a few leaves but apart from that it looked great.
We are on fairly heavy soil, but we are on a sloped valley and the drainage is good.
By way of supporting evidence, the smaller escallonia hedge plants here on the nursery (which is 300 feet higher above sea level than home) are looking fantastic. Not a brown leaf amongst them.
These plants are being pot grown outdoors, so they have perfect drainage year round.
So we say that Escallonia is pretty hardy, it's more the damp that it hates.
You can find our strongly-suspected-to-be-frost-hardy escallonia hedge plants here.
Watch your garden grow and enjoy.