Uses | Plant raising | Planting | Aftercare for rock plants
Rock garden perennial flowers are mainly used in rockeries, but the smaller ones can also be grown in alpine beds, and the trailing types are suitable for planting in a dry stone wall. The larger kinds can be used at the front of borders, or as edging near pathways and paved areas.
Many kinds of rockery plants are raised from seed sown indoors in April or September. However, the range of seed available is not great, except from specialist societies such the Alpine Garden Society. Most plants are raised by dividing existing plants in October or March, or by taking cuttings of the spreading types between June and September.
Being mountain plants, the majority of them like open, sunny conditions. They are smaller than their lowland cousins because they have adapted to the shortage of soil, moisture and nutrients. Provide them with conditions of very free drainage, and adequate, but not very rich, soil.
The top 10 -15 centimetres of a rockery should be mixed specially, using two parts soil, one part peat and one part sand or grit. Alternatively, coarse sand or fine gravel could be dug into the top layer. Plant in October or March/April. Watch for snails.
Aftercare for rock plants
Keep rock garden plants free of weeds – they just cannot compete. A layer of gravel, grit or chippings helps to prevent weeds, and sets off the plants well. Although rockery plants like free drainage, they are used to regular rainfall and will need to be watered in prolonged dry spells. Many rockery perennials self-seed. This may not be desirable, and can be prevented by trimming off the flower heads after flowering.