Basically, both the common boxwood (Buxus sempervirens) and the small-leaved or Japanese boxwood (Buxus microphylla) are sufficiently hardy for local weather conditions and do not require any additional winter protection - at least as long as they are planted out in the garden. A boxwood in a pot, on the other hand, relies on effective insulation against frost.
How can I protect a boxwood on the balcony in winter?
To protect a potted boxwood on the balcony in winter, wrap the pot with insulating material, place it on a thick plate and place it on a house wall in partial shade. Water the plant regularly even in winter.
Boxwood in a pot needs winter protection
The reason for this is the small amount of soil that surrounds the roots of the boxwood in the pot and cannot protect them from freezing. The substrate layer is too thin for this, which is why you have to help with insulating material in winter, such as a gardener's fleece (€7.00 on Amazon). Wrap the pot with it and also place the planter on a thick wooden or Styrofoam plate. This will prevent the frost from reaching the bottom of the pot and into the roots. It also makes sense to move the plant directly against a house wall and, ideally, to place it in partial shade - sun plus frost often leads to frost damage.
Tip
The boxwood needs water even in winter, so don't forget to water it!
