The Rock Garden is home to many plants that cannot be grown elsewhere in the garden. With rocks and stones, habitats can be created that differ, for example, in terms of temperature and sun exposure, temperature and soil. Common for them all is the good drainage. Thanks to the the stones, the Rock Garden heats up faster than other parts of the garden, and flowering starts early in the spring.
Most of the plants come from alpine areas. They are adapted to cold, dry winters, windy conditions and high light levels. As a result, many of them have a modest stature. Some species grow at the limit of what they can tolerate in terms of climate, but can be grown here thanks to the favorable conditions in the Rock Garden. Several large bushes of ephedra (genus Ephedra) are found in the Rock Garden. Ephedras are gymnosperms, just like conifers.
To the south, different species and cultivars of rhododendron (Rhododendron) grow. It is a large genus with over 1000 wild species and many more cultivars. In the Botanical Garden, the different evolutionary lineages within the genus that occur in temperate climates are represented.
Saxifrages, Saxifraga, is a large genus contaning about 470 species. They mostly occur in mountainous regions of the Northern Hemisphere. Many are low and compact to tolerate wind, cold and dehydration. The leaves are often small and compared to the foliage, the flowers can seem huge!
About 17 species of saxifrages occur naturally in Sweden, among which meadow saxifrage, S. granulata, is perhaps the most widely known. In the Rock Garden there are about 30 different species and additionally a number of subspecies and varieties of saxifrages from all over the world.