Didymochlaena truncatula aka Mahogany Fern

Didymochlaena truncatula is an evergreen fern. Its common names are mahogany fern and tree maidenhair fern. Kew gives its native range as western and central Malesia. It grows in a wet tropical climate and lives for many years. It is not native to Britain or Ireland. Its old names include Aspidium truncatulum and Didymochlaena lunulata. Plant lists or old texts may use these names.

The plant grows upright in a tuft with long fronds. Its leaflets are wedge-shaped. New fronds have red tones, then turn mid-green. The leaves stay green all year. RHS gives its garden height and spread as 1.6–3.3 feet [0.5–1 metre]. RHS also notes that plants can grow taller than this. Chicago Botanic Garden gives a height of 4 feet [1.2 metres]. These accounts suggest leaving room for a large fern. RHS says plants take five to ten years to reach full size.

Grow this fern in bright light screened from direct sun. RHS lists part shade. Chicago Botanic Garden lists full shade. Both say it needs moist growing conditions. RHS also calls for good drainage and high humidity. This means water must drain well, and the air must stay moist. Under glass, use compost rich in humus. RHS lists loam soil, which may be acid, neutral, or alkaline. Choose a site with shelter. RHS lists sites that face east or west as suitable choices.

Grow this fern indoors, in greenhouses, or in conservatories. Chicago Botanic Garden also lists beds, borders, and specimen planting. Its upright shape and long fronds form a leafy focus. RHS gives it a hardiness rating of H1B. This allows outdoor growth in summer within the stated range of 50–59°F [10–15°C]. Chicago Botanic Garden lists USDA zones 9–11. These ratings use different systems. They do not mean the same thing.

RHS reports few routine problems with pests or disease. The fern needs no regular pruning. Growers can raise new plants from spores. They can also split plants they already have. The supplied sources give no details on parts people can eat. They give no details on uses as medicine, either. Nor do they give clear proof of safety for people or pets. These gaps do not mean the plant is safe to eat or harmless.