Polypodium appalachianum

Common Names

Rock Polypody, Appalachian Polypody, Appalachian Rockcap Fern

Summary

Polypodium appalachianum, commonly called Appalachian polypody or Appalachian rockcap fern, is an evergreen rock fern native to eastern North America. It grows from a creeping rhizome to form dense mats and large clonal colonies, with fronds up to about 18 inches tall and 12–24 inches across; the blade is widest at the base, and sori are round on the underside. It commonly grows on moist rocks in shaded, cool forests and ravines, often on north-facing outcrops, and can be epiphytic in the Smoky Mountains. In cultivation it tolerates heavy shade and moist, acidic soil (pH 5.0–6.5) with good drainage, and is best planted in early spring or fall, spaced 12–18 inches apart; containers are possible with large pots, good drainage, and consistent moisture. Hardy across USDA zones 3a–8b, it reproduces by spores or division, with spores germinating in about 2–4 weeks under humidity and indirect light and division by splitting rhizomes. Regular maintenance includes pruning dead fronds and keeping soil evenly moist to avoid waterlogging; common problems include powdery mildew, rust, blight, and root rot, and pests such as spider mites, scale, and mealybugs may occur, for which organic controls are recommended. Not toxic to dogs or cats. In landscape settings, it suits native shade gardens, rock slopes, and woodland understories, providing aesthetics, erosion control, wildlife habitat, and improved air quality in shaded spaces.

Lifecycle

Perennial

Height

6-12 inches

Spread

6-12 inches

Hardiness Zones

Zones 3a-8b

Sunlight Requirements

Ideally partial shade.

Soil Type

Rocky, shallow, acidic, well-drained soil (pH 5.0–6.5), often thin over rock, on sandstone or other hard, noncalcareous rocks

Soil Drainage

Soil drainage isn’t applicable, it doesn’t grow in soil

Soil pH

5.0-6.0, Acidic

Bloom Time

Summer to Fall

Foliage Color

Green

Fall Foliage Color

No fall foliage color

Leaf Lifecycle

Evergreen broadleaf

Growth Rate

Moderate

Seasons of Interest

Summer and Fall

Propagation Methods

Spores, Division

Attracts Wildlife

Attracts birds