FIRST IMPRESSIONS: Polystichum acrostichoides is a mounding perennial fern with lustrous evergreen arching fronds. Foliage is once compound with each impressive frond consisting of many pairs of serrate pinnae. This fern thrives in moist sites and adapts to loamy soils in shade or part shade.
HABITAT & HARDINESS: Polystichum acrostichoides occurs in central and eastern North America. The range extends through the southeastern Canadian provinces and from Minnesota to Maine and south from Texas to Florida.
Plants are indigenous to deciduous woodlands including bluffs, sloping ravines, creek banks, mesic and upland woods. This fern is most likely to be found in hilly woods dominated by deciduous trees where limestone or sandstone is close to the ground.
Hardiness rating is from USDA Zones 3-9.
PLANT DESCRIPTION: Polystichum acrostichoides is a mounding evergreen fern that emerges from stout dark rhizomes. Plants occur alone or in small colonies.
In early spring slender silvery fiddleheads emerge from the loose tufts of old foliage. Old leaves collapse into the leaf litter as new fronds unfurl from the fiddleheads.
The leaves are once compound and about 2’ long and 4” across. Each frond consists of 10-20 pairs of oblong leaflets attached by very short stalks to a scaly rachis.
The leaflets are staggered on the rachis and are lustrous and leathery with fine teeth. Leaflet bases are usually asymmetrical or oblique and are flared out into a bump on one side.
Some leaflets located toward the tip of the rachis are fertile with chocolate brown sori beneath.
Typically this fern is about 2’ tall with an equal spread.
CULTURAL & MAINTENANCE NEEDS: Polystichum acrostichoides grows best in dappled or full shade.
This is an adaptable fern that thrives in mesic or slightly dry loamy soil covered by layers of leaf mulch. Plants require good drainage and are often found on slopes. They tolerate rocky soil and acid to neutral pH.
In garden situations, soil should be amended with organic matter and irrigated during long periods of drought.
Plants are remarkably pest resistant and tolerate some drought after establishment.
This is a pest resistant fern that is unpalatable to deer and other herbivores.
LANDSCAPE USES: The lustrous evergreen foliage of this fern provide Winter Interest and allow it to serve as a lovely and useful Accent for a Shade Garden. In appropriate sites, Polystichum acrostichoides matures into a verdant and soothing Groundcover, Border or Mass. This fern provides Erosion Control and serves as a valuable component of Deer Resistant Plantings, Low Maintenance Plantings, Perennial Borders, Rock Gardens, Water-Wise Landscapes and Wildlife Gardens.
COMPANION & UNDERSTUDY PLANTS: Try pairing with Aquilegia canadensis, Carex plantaginea, Phlox divaricata, Silene virginica or Viola walteri ‘Silver Gem’.
Dryopteris marginalis is an evergreen fern with similar cultural needs that can be substituted if needed.
TRIVIA: This fern is commonly called Christmas fern because the evergreen fronds have been used in holiday decorations.
The basal flare on one side gives the leaflets an unusual shape. The pinnae are said to look like Santa in his sleigh or like Santa’s boot.
Tender young fronds are sometimes eaten by upland gamebirds like Ruffed Grouse and Wild Turkey.
For more information on this plant, visit the USDA PLANTS Database: http://plants.usda.gov/java/profile?symbol=poac4