Hardy in zone 3-9, Christmas fern, Polystichum acrostichoides, matures at 2' in height and spread. Native to the north-central and eastern portions of the United States, they do well in acid to well-drained, neutral soil. Full to part shade, such as found in a native forest, is the ideal light requirement. Though these can be found in the wild in many parts of the country, they are easily obtainable commercially.
Christmas fern is thought to have been so named because it is evergreen. It was one of the few things available to early pioneers to decorate with for the holidays. Unlike many plants that go dormant, this fern retains its vibrant green color throughout the winter months. That makes it a desirable choice for homeowners who wish to brighten shady areas, even in the depths of winter. Snow may cover them temporarily, but they will be peeking out, bright green, as soon as they can.
Their fronds are bright glossy green with an attractive pattern. They fit in well with woodland settings, mixing well with hostas, trilliums, and other shade lovers. Since they are evergreen, the area will remain attractive even when the companion plantings are not visible. They are handy for shaded hillsides, where it can be hard to establish other plants. They are handy for the prevention of soil erosion. Unlike many plants that thrive in a woodland setting, these are not the favorite food of rabbits or deer, so they are favored by homeowners who have had problems with wildlife eating the landscape.
Christmas ferns are very easy to grow. They are almost maintenance-free. They do not need heavy feeding with expensive fertilizers. They only ask for shade and adequate moisture. One can grow their crop of ferns if they want to try a few methods of propagation. The easiest is to divide the crown every three years or so. Another way is to grow them from spores; Ferns have spores on the undersides of their fertile fronds. These are longer and larger than the infertile fronds. When the spores are ripe, usually around late summer, they will drop, and if the area around the fern is hospitable, new ferns will sprout. That can be encouraged by keeping the area free from debris and even sprinkling fine soil, such as a seedling mix, around the base. Keeping the area damp but not saturated is essential at this time. To control this, one could scrape the spores off the fronds and try it in pots.
Christmas ferns themselves can be used in pots alone or with mixed planting. That would be very useful to brighten up dark areas where flowers would be impossible — no need to replant pots every year as the ferns are evergreen and perennial. If the area is shaded because of an overhang, remember to supply additional water as needed.