Hardy plants can withstand the Dutch winters and the freezing cold that comes with it. These plants protect themselves from the cold. Some do this by dying off above ground, hibernating underground, and blooming again in the spring. Therefore, do not immediately assume that the plant is dead, but wait until spring and who knows, the first leaves will appear again.
Examples of hardy plants
Skimmia and Calocephalus: these are ideal plants for flower pots. The Skimmia has fragrant flowers and striking berries in winter. The Calocephalus is characterized by its grey-green leaves.
Japanese Maple: a beautiful tree whose leaves turn red in the fall and which resist frost well.
Clematis (forest tendril): these hardy plants with purple or white flowers can withstand freezing cold.
Camellia: there are more than 1000 species of Camellias, so plenty of choice. They can withstand freezing temperatures and are one of the first plants to flower in spring.
Semi-hardy plants can withstand frost, but not too severe and too long frost. With these plants it is therefore best to cover the ground with some bark, hay or old branches to protect them against severe frost. In this video you can see a number of examples of semi-hardy plants: