The maidenhair fern or botanically Adiantum raddianum [ ad-ee-AN-tum, rad-dee-AY-num] is a member of the Pteridaceae family and one of the most popular fern species for growing indoors.
While it is native to the tropical and subtropical regions of South America, where it is seen growing on rocks or terrestrially.
The genus name Adiantum comes from the Greek word “adiantos,” which means “unwetted,” a very good description of the leaves.
The plant has also become naturalized in many tropical and subtropical islands and is considered invasive in French Polynesia and Hawaii.
It is also grown as an ornamental plant in many parts of Africa, Asia, Europe, and the Pacific.
Other Adiantums known as “maidenhair fern” include:
- Adiantum capillus-veneris
- Adiantum pedatum
- Adiantum aleuticum known as the (Northern maidenhair fern)
Adiantum Raddianum Care
Size & Growth
A delicate and short fern species, Adiantums grow out of short rhizomes and the wiry stems reach up to the height of about 17” – 19” inches.
However, it can have a spread of up to 23” inches.
One of the major reasons for the popularity of maidenhair ferns is because it spreads readily and is highly adaptable to different environments.
Its dark green, triangular fronds comprise numerous tiny wedge-shaped leaflets resembling human hair.
This is why the plants’ common name is maidenhair.
The green fronds are delicate and semi-erect in the beginning, but start to droop (gracefully) as the plant matures.
Depending on the growing conditions, the fronds can grow up to 7” – 8” inches in length.
The bases of frond stalks and the short, creeping rhizome of this herbaceous perennial plant are covered with tiny, dark brown colored scales.
Flowering and Fragrance
Adiantum is a fern and a non-flowering plant.
Light & Temperature
Adiantum ferns grow best in highly humid conditions where it can get direct sun and it does not like dry air.
While the fern species prefers shade and grows best in areas where it receives small amounts of filtered sunlight, it cannot survive in full shade without any sunlight.
Since it is often difficult to maintain adequate humidity levels when the fern is grown as a houseplant, experts recommend using a humidifier or placing the pot on a tray filled with moist pebbles.
Mist the plant or double pot it to make sure it gets the required amount of humidity.
For those who do not know, double potting involves placing the pot of the plant in a larger pot filled with peat moss.
The ideal temperature is 65° – 75° degrees Fahrenheit (18° C – 24° C) for delta maidenhair fern.
The plant is winter hardy to USDA hardiness zones 10 and 11.
Watering and Feeding
The plant requires a constant supply of moisture from both soil and atmosphere to grow properly, so make sure to water it regularly and never let it completely dry out.
Also, be careful not to overwater the fern as it can cause yellowing of frond tips and root rot.
Application of diluted fertilizer, once a month, from April to September encourages healthy growth.
Use liquid fertilizer after watering to prevent the burning of roots.
Fertilize monthly year-round with half-strength liquid fertilizer.
Soil & Transplanting
Plant Adiantum in a peat-based potting mix with organic matter.
Since excessive water can cause problems for the plant, it is recommended to keep the potting mixture a little loose to ensure proper drainage.
The fern doesn’t need to be transplanted too often – repotting once every two years is enough.
Spring is the best time for transplanting the maidenhair fern.
Grooming and Maintenance
To ensure proper growth, make sure your maidenhair fern is getting an adequate amount of humidity and moisture.
If the leaflets dry out or fall off due to a lack of humidity, prune the plant by cutting the black stems off at the base.
Increase the humidity levels and maintain soil moisture so new growth will appear.
Misting the plant is recommended twice a day, after pruning, until the new shoots begin to grow.
Make use of a pebble tray to maintain humidity levels.
How to Propagate Adiantum Maidenhair
Divide the Adiantum raddianum plant, while leaving the rhizomes attached to a couple of fronds, at the time of repotting in early spring or when the plant has outgrown its container to propagate.
While ferns do produce spores, they are difficult to grow.
However, the plant type readily spreads through spores in its natural habitat.
Adiantum Pest or Diseases
Adiantum raddianum plants do not get affected by any serious pests.
When grown in pots, the uncurling fronds of the fern can get attacked by aphids.
Special care needs to be taken with watering as excessive moisture, and stagnant water can cause a grey mold.
On the other hand, too much exposure to sunlight or a lack of fertilizer can cause scorch marks on fronds or their paling, respectively.
The tips of fronds turning brown is a sign of a lack of humidity.
Maidenhair Raddianum Uses
Despite the fact southern maidenhair fern requires high humidity consistently, which is difficult to provide in homes, it enjoys high popularity as a houseplant.
Planted in containers, pots, or hanging baskets, place Maidenhair ferns on terraces, patios, pergolas, and even indoors to liven up the settings. However, try to keep them out of windy locatons.
This North American native specimen is great on its own but it also makes a great ground cover, beautiful in a woodland garden, or in a terrarium.