Polystichum are known mainly as outdoor ferns in northern Europe. Polystichum munitum, much prized by florists, belongs to this genus. It was originally imported from North America and its fronds are used as greenery with flower arrangements and bouquets. It is almost exclusively Polystichum tsus-simense that is found for sale as an indoor fern. This small species took its name from a group of Japanese islands called Tsushima. In diameter it is about 15-20 cm (6-8 in) and it grows to a height of about 30 cm (12 in). Its leaves are oval, longish and bipinnate. The leaf stalks have many dark brown scales in their lower sections and are hairy further up. The round clusters of, which have shield-shaped veils, form two regular rows between the edge of the leaf and the central rib of the leaf.
This fern has a particularly attractive appearance due to its dark green, leathery fronds. It is, however, also of interest because of its preference for cooler positions. It is even hardy in regions that are warm enough for grapevines to grow, provided it is protected with a covering of dead leaves.
Origin: This genus is distributed worldwide in temperate to subtropical regions. The plants grow terrestrially, often in mountainous forests and along the banks of rivers. Polystichum tsussimense originates from Korea, Japan, China and Taiwan.
Position: Bright but not sunny. This plant can cope with cooler temperatures between 12° C and 16° C (54-61° F) and even as low as 5° C (41° F) during the night.
Care: Keep evenly moist during the growth phase. Water less during the winter but do not allow it to dry out. Give low doses of fertilizer weekly from the first month of spring to the first month of autumn. With its leathery leaves, this fern can cope with drier air but is also grateful for the occasional misting. Repot annually in the spring.
Propagation: From division or.
Pests, diseases: None known.
My tip: Polystichum tsussimense is eminently suitable for bottle gardens because of its small size.