Double pot your container plants
If this winter is anything like the last two winters then you need to take extra care with all your container plants. Even
if the plants are hardy they can still succumb if their roots are frozen for long periods. Rather than planting directly into your ornamental container it is better to plant into a cheap plastic pot slightly narrower than your ornamental pot. Fill the airgap with polystyrene chippings or bubblewrap to give extra protection to your plant roots. You can disguise the double potting by covering the surface with some bark or gravel. If the weather is freezing for a long spell it is lighter to just remove your plant in the plastic pot than to try to struggle with the heavier ornamental pot and place it somewhere frost free.
Many plants, especially shrubs, have been lost over the last two years because they died of drought. They do not show this damage straight away so gardeners are often unaware that this is the reason that the plant has died. Even on frosty days the sun can be warm enough to make a plant require water. If the roots are frozen then the plant is unable to quench its thirst. The result will be a dead plant at some time in the future.