Culture
Grow in organically rich, fertile, consistently moist, well-drained soils in part shade to full shade. Best in bright but sun-dappled or filtered light in sheltered locations with good air circulation. Part shade is better than full shade. Container plants grown as houseplants should be placed near sunny windows but not in direct sun. Foliage may scorch in full sun but growth will lose vigor in too much shade. Water freely and evenly, but avoid overwatering. Soils should never be allowed to dry out. Mist foliage to increase humidity. Best indoor daytime temperatures are around 70 degrees F., dipping to 60 degrees F. at night.
Noteworthy Characteristics
Adiantum hispidulum, commonly known as rough maidenhair fern, is an evergreen to deciduous fern featuring bipinnate to tripinnate fronds (each to 14” long). It typically grows in an arching foliage clump to 12-18” tall, spreading over time by wiry, short-creeping rhizomes to form small colonies. Each frond is divided into narrow pinnae stemming from the center stem of the frond, with each pinna being clad with rough textured, oblong to fan-shaped, medium to dark green pinnules (leaf segments to 1/2” long). Each pinnule has sori (spores) which appear in summer on the undermargins of the pinnules (6-14 sori per pinnule). This fern is native to shaded rainforest and open rocky sites, often found along rivers and banks, in Australia, New Zealand, Pacific islands, tropical Asia and Africa. It has escaped gardens and naturalized in certain parts of the southern U. S. (Louisiana, Alabama, Georgia, Florida, and Hawaii). This fern tends to be deciduous when grown outdoors in temperate conditions of USDA Zones 8-10, but is semi-evergreen to evergreen when grown in semi-tropical to tropical conditions or indoors as a houseplant. Juvenile foliage emerges showy pink in sharp contrast to the leathery dark green mature foliage, hence the sometimes used additional common name of rosy maidenhair fern. Pink fronds gradually mature to dark green or bronze green. Common name of rough maidenhair fern is in reference to its rough-textured foliage.
Genus name comes from the Greek word adiantos meaning unwetted in reference to the water repellent foliage.
Specific epithet comes from Latin hispus meaning hair in reference to the fronds having minutely hairy stems.
Problems
No serious insect or disease problems. Leaves may scorch in direct sun. Rhizome rot may occur in wet soils. At the other extreme, fronds will die back quickly if soils are allowed to dry out. Watch for aphids, mealybugs and scale.
Uses
This is a popular ornamental fern which may be grown outdoors in USDA Zones 8-10 (perhaps Zone 7 if mulched and sheltered in winter) in shaded areas of woodland gardens and/or in containers/hanging baskets in shaded patio areas. North of Zone 8, it is usually grown indoors as a houseplant.