FIRST IMPRESSIONS: Dryopteris marginalis is a clump forming perennial fern with upright feathery fronds. Foliage is twice compound with each impressive frond consisting of many pairs of small narrow leaflets. Foliage is evergreen with a soothing blue green color. This fern thrives in moist loamy soils in dappled sun or partly shaded exposure. Plants are prized for their ability to adapt to difficult dry shaded sites.
HABITAT & HARDINESS: Dryopteris marginalis ranges from Newfoundland to Georgia and west to Minnesota and Oklahoma.
Plants are indigenous to rocky shaded sites including rocky woods, ravines and bluffs, shaded rock crevices and wooded rocky slopes. This fern is often associated with sites where sandstone is exposed at the ground surface.
Hardiness rating is from USDA Zones 3-8.
PLANT DESCRIPTION: Dryopteris marginalis is an evergreen clumping perennial fern that produces large rosettes of arching leathery blue green leaves. Plants have stout rhizomes and occasionally produce small colonies.
The fronds are twice compound and 12” to 30” long and 4-9” across. The entire frond is lanceolate or spearhead shaped with a long slender tip.
The petiole or leafless part of the stalk is about 3-10” long and is light green with brown chaffy scales.
About 12-20 pairs of leaflet units or pinnae originate on the rachis above the petiole. Each has 8-20 linear or lanceolate subleaflets or pinnules.
Sori or spore clusters form beneath the pinnules along the margin. This marginal sori location is very unusual and is the best ID characteristic for this fern.
This fern is 1-2’ tall with an equal spread.
CULTURAL & MAINTENANCE NEEDS: Dryopteris marginalis grows best in dappled to light shade with low to medium moisture. Plants tolerate rocky soil with neutral to acid pH but are adaptable to many soil types.
This delicate looking beauty is easy to grow and low maintenance. Plants are remarkably pest resistant and drought tolerant once established. For best appearance, fronds should be sheltered from excessive wind.
As it matures into lush groundcover stands this fern provides valuable habitat for small wildlife. This pest resistant fern is not palatable to deer and other herbivores.
LANDSCAPE USES: The dramatic feathery foliage of this fern make it a lovely and useful Accent for a Shade Garden. In appropriate sites, Dryopteris marginalis matures into a verdant and soothing Groundcover or Mass. This fern can control erosion on dry shaded banks and serve as a valuable component of Deer Resistant Plantings, Low Maintenance Plantings, Perennial Borders, Rock Gardens and Wildlife Gardens.
COMPANION & UNDERSTUDY PLANTS: Try pairing with Carex appalachica, Heuchera villosa, Phlox divaricata or Stylophorum diphyllum.
Adiantum pedatum has similar cultural needs but will not tolerate as much drought.
TRIVIA: Determining the type of leaf arrangement is the first step in identifying a fern. If in doubt, imagine that a small bug is crawling from the ground to the top of the petiole. The bug is programmed to turn right at every opportunity. If after making one turn, the insect ends up at the tip of a leaflet, the leaf is once compound like Polystichum acrostichoides. If the bug turns onto a stalk and then makes a second turn to reach the tip of a subleaflet, the leaf is twice or bipinnately compound like those of Dryopteris marginalis.
For more information on this plant, visit the USDA PLANTS Database: http://plants.usda.gov/java/profile?symbol=drma4