December Plant of the Month
The Christmas Fern: Polystichum acrostichoides
Christmas trees are a holiday staple for those who celebrate, but look in the woods and chances are you’ll find a Christmas fern to complement the traditional festive greenery. Specifically, THE Christmas Fern: Polystichum acrostichoides. A distinctive native fern that’s easy to identify, Christmas Fern stands out for its rich green color, prominent scales along the stalks, and leathery, evergreen fronds with asymmetrical leaflets. Its evergreen nature gives it its common name. Early European colonists often used this plant as a Christmas decoration, a practice that still continues for some. Some say that the name refers to the stocking-shaped leaflets along the fronds, though I’ll be honest and admit I don’t see it. Happily, Christmas Fern is a common species, so you can easily find it and decide for yourself.
Though it has a preference for moist, well-drained, and shaded woodlands, it’s surprisingly drought-tolerant and adaptable. Christmas Fern is able to handle quite a bit of sun with sufficient moisture, but truly thrives in shade. Unlike some of our weedier native ferns, Christmas Fern is not a colony-forming species; it is usually found individually or in loose associations. Despite that, its dense fibrous root system provides excellent erosion control for the slopes its often found growing upon. Their annual pattern of growth and dieback relating to their reproductive cycle helps break down forest duff into humus, enriching the forest floor.
That being said, like many ferns, its ecological value is fairly low. These are tough plants with almost no predators. It has a specialist aphid; turkeys will occasionally feed on the youngest fronds; deer might nibble at it sparingly in particularly bad winters; and that’s about it. But its adaptability, deer resistance, evergreen good looks, and ability to grow in deep shade make it a fantastic plant for the woodland garden, with caveats. Make sure any plants you purchase are nursery-propagated. While still a fairly abundant plant, like almost all other fern species in New York, Christmas Fern has special conservation listing as being Exploitably Vulnerable state-wide. “Exploitably vulnerable” refers to plant or animal species which aren’t threatened or endangered yet, but are at risk of becoming so in the future. So, don’t harvest plants from the wild and enjoy their holiday cheer outdoors.
Mathew McDowell, Wildflower Island Curator