The Sunset Western Garden Book calls it the “most-seen fern of the redwood forests,” but because it is so versatile and hardy, the sword fern, or polystichum munitum, is also seen in gardens throughout the country. Growing in sun or shade, with and without regular watering, both indoors and out, the sword fern is a good choice for most any garden.
Ferns are ancestors of a prehistoric plant millions of years old in the class called pteridophyta. These plants were once the most common plant on earth, and visitors to natural history museums will notice them alongside the dinosaur displays. Many fossils show the distinctive frond shapes and young spiral buds of ferns.
The Plant Itself
The dark green, shiny fronds on sword ferns can reach 4 feet in height, with the plant itself spanning 8 feet in width. Some old plants can have as many as 75 to 100 fronds. Because the fronds are tough and durable, they are generally deer-resistant and also do well in cut flower arrangements.
While sword ferns are native from California to Alaska and Montana, they can easily be grown in a rich, organic soil if they are provided with plenty of water. Sword ferns do best in shade but can also grow in partial or even full sun in areas where the summers are not too hot. The ferns are frequently used by gardeners along shaded house walls or as part of the flower bed in a large-scale mixed woodland type of landscaping.
Like all ferns, the sword fern reproduces from spores instead of through flowers, seeds or brackens. These microscopic spores are housed in small bumps, called sporangia, arranged in rows on the underside of the fronds. These spores drop to the ground and germinate to form a new plant called a gametophyte, which contains both the male and female organs of the fern. The actual fern grows out of the gametophyte.
Care and Maintenance
Garden soil needs organic amendments to create the rich, well-draining soil that sword ferns need to thrive. No additional fertilizer is necessary. To help keep the soil moist, add a layer of organic mulch such as leaves or fir needles. The new growth on sword ferns needs the older growth to help sustain it during the growing period, so it’s best not to remove older fronds until they are dried and brown, unless you do want to limit the size of the fern.