Deparia petersenii

Common Name: Japanese lady fern 
Type: Fern
Family: Athyriaceae
Native Range: Southeastern Asia
Zone: 6 to 9
Height: 1.00 to 2.00 feet
Spread: 1.00 to 2.00 feet
Bloom Time: Non-flowering
Bloom Description: Non-flowering
Sun: Part shade to full shade
Water: Medium to wet
Maintenance: Medium
Suggested Use: Naturalize
Tolerate: Rabbit


Easily grown in average, medium to wet soils in part shade to full shade. Prefers moist, rich, humusy soils. May not be reliably winter hardy throughout USDA Zone 5 where it should be grown in a protected location. Consider leaving dead fronds as a winter mulch.

Noteworthy Characteristics

Deparia petersenii, commonly called Japanese lady fern or black lady fern, is a deciduous fern which typically grows to 18" tall (occasionally to 24") and as wide. Features attractive blackish-green, upright arching, triangular fronds. Sori are arranged in a herringbone pattern on the undersides of the pinnae. Fiddleheads begin to unfurl in late spring after most other ferns are already leafed out. Spreads slowly by creeping rhizomes. Synonymous with and sometimes sold as Athyrium japonicum or Lunathyrium japonicum.

Genus name comes from the Greek word depas meaning saucer in reference to the saucer-like indusium that covers the sori.


No serious insect or disease problem. Winter hardiness in the St. Louis area is a concern.


Mass or group in woodland or shade gardens.