If it snows heavily and for long periods at temperatures of around 0 degrees Celsius, you can observe how the branches become increasingly heavy and slowly bend towards the ground. They can no longer keep themselves upright with their own strength. Normally the branches and twigs only right themselves again properly if the snow load has only been on them for a short time. However, already after only a few hours, their wood is usually so stretched that it no longer straightens itself again. For this reason, speed is of the essence as soon as an excessive snow load is visible on branches and twigs. Take a broom, for example, and shake or sweep snow carefully from the twigs in order to prevent branches breaking. If it snows heavily, you may have to repeat this.
Too much snow on plants which grow in a bed or have thick growth is not harmful, incidentally, but even provides additional protection from the cold.