How to care for maidenhair fern (Adiantum raddianum)

Adiantum raddianum · Delta maidenhair fern

Maidenhair fern (Adiantum raddianum) — a delicate tropical American fern with lacy, arching fronds of small, fan- to triangle-shaped leaflets on shiny black, wiry stalks. It forms a clump about 30–50 cm tall and wide and has no flowers. Maidenhair fern needs partial shade and 16–21 °C. Water it about every 3 days while it grows and about every 7 days in the winter rest.

Checked against sources: November 5, 2026

Watering and repotting maidenhair fern through the year

It lives indoors all year, so it has no sowing or planting dates: it grows from March to September and rests from October to February (the other way round in the southern hemisphere).

Repot it about every 24 months.

When to plant maidenhair fern?

Plant or repot maidenhair fern in spring, as it starts into growth; early to midsummer also works. It is a houseplant, so it has no outdoor planting date and no frost decides it: just avoid autumn and winter, when growth slows and fresh compost stays wet too long. After that, move it to a slightly larger pot about every two years, or sooner once roots circle the pot or grow through the drainage holes.

Watering in the growing and resting halves of the year: Watering and repotting maidenhair fern through the year.

Sources: RHS: How to repot a plant · Penn State Extension: Repotting houseplants

Quick facts

Type	Houseplant
Latin name	Adiantum raddianum
Family	Pteridaceae
Also called	Delta maidenhair fern
Light	Partial shade
Frost	does not tolerate frost
Repotting	every 24 months
Grown in	At home

Where does maidenhair fern grow?

9,354 records of the plant in gardens, fields and the wild worldwide; most photos come from New Zealand, Brazil, United States, Peru, and Portugal.

World map: where maidenhair fern has been recorded — Darker green means more records. Photos are real observations from those countries — tap one to see it. Map and records: GBIF.org (2026-10-28), © OpenMapTiles © OpenStreetMap. Photo: naturewatchwidow, Vítor Sanchez, Tara Severns, alvarogiraldezguerrero22, Analía Belaus, Adele SL, Eamonn Culhane, andrew2285 (CC BY / CC0).

Maidenhair fern, New Zealand — Darker green means more records. Photos are real observations from those countries — tap one to see it. Map and records: GBIF.org (2026-10-28), © OpenMapTiles © OpenStreetMap. Photo: naturewatchwidow, Vítor Sanchez, Tara Severns, alvarogiraldezguerrero22, Analía Belaus, Adele SL, Eamonn Culhane, andrew2285 (CC BY / CC0).

Maidenhair fern care by growth stage

At home

Stage	Watering	Temperature	Feeding
Growth	every 3 days	16…21 °C	balanced (NPK), 14 days into the stage; balanced (NPK), 44 days into the stage; balanced (NPK), 74 days into the stage; balanced (NPK), 104 days into the stage; balanced (NPK), 134 days into the stage
Winter rest	every 7 days	—	—

Growing notes

Light

Bright, indirect light with good ventilation; the light of a north-facing window is ideal. Full sun scorches the delicate fronds, while too deep shade weakens the plant.

Soil

A porous, peat-free houseplant compost rich in organic matter that stays moist but drains freely; the roots must not sit in waterlogged compost.

Care

One of the fussier ferns to keep indoors. In spring and summer keep the compost moist at all times and never let the roots dry out, but do not leave the pot standing in water; in winter water sparingly. It needs high humidity, around 50 % or more, so stand the pot on a tray of moist gravel or grow it in a bright bathroom or a terrarium; dry air quickly browns the thin leaflets. It likes 16–21 °C by day and about 5 °C less at night. Feed monthly from mid-spring to late summer with a general liquid fertiliser at half strength. Cut off dead fronds, and divide crowded clumps by splitting the rhizomes in early spring. Watch for scale insects and mealybugs; many ferns are harmed by insecticide sprays, so test any product on a small part first.

Pests and diseases of Maidenhair fern

1 problem is recorded for maidenhair fern; it has a page with symptoms, treatment and prevention.

Pests

Scale insects

Plant lists it is in

Part of: Houseplants · Thirsty houseplants

Sources

Figures checked against these sources.