Polystichum acrostichoides [pol-IS-tick-um, ak-ruh-stik-OY-deez] is a perennial, evergreen fern from the family Dryopteridaceae (wood fern) and is native to eastern parts of North America.
The plant is given the common name Christmas fern because its evergreen fronds maintain their vibrant green color even at Christmas time, when the weather in its native range gets extremely cold, and can thus be used in decorations.
Christmas Fern Care
Size & Growth
Polystichum acrostichoides has a unique structure– it features an arching clump of tall fronds attached to a tiny stalk, which is supported by a central rhizome.
The dark-green, glossy fronds are of two types, fertile and sterile, and can grow up to 1’ to 2’ feet tall lasting year-round.
The sterile fronds are shorter than the fertile ones, are located on the outer side of the clump, and form an arching, encircling border around the erect fertile fronds.
The plant also produces silvery fiddleheads in early spring.
Provide the right conditions and your Christmas fern will quickly grow and establish itself.
But, unlike most rhizomatous plants, it does not spread too much or naturalize.
Flowering and Fragrance
Polystichum acrostichoides is a non-flowering plant.
Light & Temperature
This fern species grows best in part shade to full shade. The fronds become pale when the plant is exposed to too much sun. Excessive sun exposure will cause stunted growth.
This plant type may tolerate some sun if the soil has adequate moisture, but since it thrives in the shade, it’s recommended to plant it in at least a partially shaded area (shade garden) and protect from very cold weather for proper growth rate.
USDA hardiness zone 3 – 9.
Watering and Feeding
Christmas fern doesn’t require too much watering.
While it appreciates some moisture, it can grow in slightly dry soil as well.
However, excessive dryness will cause the leaves to droop.
Watering once a week is enough to maintain just the right amount of moisture to support growth.
Start feeding the plant with a granular fertilizer from the second spring season after planting.
Fertilizing once a year is enough.
Soil & Transplanting
Polystichum acrostichoides thrives in organically rich, and well-draining sandy or rocky soils.
While it can grow in other types of soils as well, the fern cannot tolerate clay and water-logged soils.
Transplant to ground after the end of the frost season and leave about 18” inches of space between plantings to avoid overcrowding.
Also, apply a thick layer of leaf mulch, shredded bark, or pine needles to help retain soil moisture.
Grooming and Maintenance
Growing and caring for a Christmas fern plant requires minimal effort.
While it doesn’t need pruning, you may remove damaged or browned fronds to maintain its appearance.
It’s also deer resistant.
How to Propagate Polystichum Acrostichoides
Christmas fern is propagated by spores or root divisions.
Collect spores when they are ripe and sow them in humus-rich, moist soil at 59° – 61° degrees Fahrenheit (15° C – 16° C) in partial shade.
Spring is the best time to propagate by root divisions.
Christmas Fern Pest or Diseases
The plant is susceptible to crown rot if grown in poorly drained soil.
In addition to ensuring the soil is well-draining, experts suggest planting the rhizomes at an angle to avoid the problem.
Also, look out for mealy bugs and scale insects.
The larvae of pyralid moth will feed on Christmas fern’s sterile fronds.
Polystichum Acrostichoides Uses
Since this fern species doesn’t like too much sun, it is best to be grown in the shaded areas of gardens. They grow alongside walls or on patios.
It is also often grown as a groundcover to prevent soil erosion even though it’s a clumping fern.
The firm, deep green leaves make it a great companion for woodland garden wildflowers.
There is also evidence the plant was historically used by many North American Indian tribes for medicinal purposes, such as for treating rheumatic joints, bowel issues, pneumonia, and fever.
However, it is not known to be used in modern herbalism.