Asplenium antiquum aka Japanese Bird's Nest Fern

Asplenium antiquum is an evergreen fern in the Aspleniaceae family. Its common name is bird’s nest fern. Its native range runs from Fujian, China, into temperate East Asia. Kew records it as a plant of subtropical climates. It can grow as an epiphyte or a perennial. It is not native to Britain or Ireland. In cultivation, gardeners grow this tender fern indoors or under glass.

The plant forms a clump of upright, glossy green fronds. These gather into a rosette that gives the fern its name. Each frond is long and flat, with a pointed tip. Wavy edges add shape to the otherwise simple outline. A brown midrib develops as each frond matures. The foliage stays green throughout the year. Plants stand about 2–3 feet [0.6–0.9 metres] tall. The RHS gives an upper garden height of 3.3 feet [1 metre]. Its spread can also reach 3.3 feet [1 metre]. Plants take five to ten years to reach full size.

Give this fern bright, indirect light when growing it indoors. The RHS also lists partial shade as a suitable position. Choose a sheltered place rather than an exposed site. It needs moist soil that lets excess water drain away. Loam and an acid to neutral pH suit it. For pots, the RHS recommends a mix based on peat-free compost. This combines three parts multipurpose compost with one part John Innes No.3. Added horticultural grit helps keep the mix open.

Keep the compost moist, but do not leave it soggy. Mist the fronds at times to provide moderate humidity. Feed monthly from May through August with half-strength general liquid fertiliser. The RHS rates its UK hardiness as H1B. This allows summer outdoor growing within the stated 10–15°C range. Houseplant displays, conservatories and greenhouses are suitable uses. Its evergreen rosette provides foliage interest through all four seasons.

This fern needs no pruning as part of routine care. Scale insects may attack it, though diseases are not usually troublesome. Propagate it by dividing the plant or by sowing spores. Sow spores when ripe and keep them at 21°C. The supplied sources give no guidance on eating this species. They also provide no species-level assessment of its toxicity.