Restios are rush-like tufted rhizomatous perennials which originate from cool and damp grassy areas in the foothills of coastal mountains in South Africa. There are around 50 species in all. Many of the tougher species can, and readily do, thrive outside in milder or coastal environments in the west of England. They are much admired as architectural plants beside swimming pools and more modern buildings as well as making wonderful features in pots on the patio or veranda which need to come back inside the greenhouse or conservatory for the winter in colder areas. In one sense they are up there with the very best ornamental grasses in any landscape design although they are not exactly ‘grasses’ in botanical terms.
All restios are dioecious in that they have separate male and female flowers on separate plants. This can add considerably to the ornamental appearance of some species where slender feathery stems produce grass-like inflorescences in the summer on brown spiklets of flowers. The leaves in restios are effectively sheath like structures that split down to the base and surround the flowering stems.
Over the years we have offered several different species of highly ornamental restios. The March 2018 Beast from the East was not exactly kind to some of the more tender varieties in Cornish gardens but others, given shelter from cold winds, have survived with some scorching. We can therefore recommend the following as better than half hardy here and certainly suitable for growing in large pots:
Chondropetalum tectrum – roof reed
This is a tufted evergreen perennial with short rhizomes and dark green stems. Its male and female inflorescences appear in late spring or summer and are superficially similar with dark brown spikelets. It grows about 18in tall with a spread of up to 3ft.
Elegia capensis
This is one of the faster growing and taller varieties producing dark brown flower heads at the tips of the stems in summer. It has large decorative papery sheaths along its stems which fall off as clumps of needle like branches appear. The male or female inflorescences unfurl at the top of the branches in late summer and can be 4-6ft tall.
Rhodocoma capensis
This is another fast growing needle like perennial with arching stems and fine foliage. It produces brown grass like flower spikes in the autumn and clumps can grow to 6ft in height. The stems have distinct nodes like a bamboo and from each node develops a thick whorl of finely divided feathery leaves.
Under glass all restios should be grown in a loam based potting compost in full sunlight. They dislike high levels of humidity so water and feed moderately in the growing season and sparingly in winter. Outside they grow best in moderately fertile acidic soil with good drainage in full sun. These plants strongly dislike being waterlogged in compacted soil.
The plants can readily be planted out in borders and lifted again for the winter in colder areas. They can readily be split and divided after lifting or in early spring.
Seed will germinate easily in spring but only after soaking in warm water for a day or so.
