Culture
Winter hardy to USDA Zones 10-12 where it may be grown in moist, humusy, well-drained soils in part shade. In St. Louis, it is easily grown indoors as a houseplant. Use a peaty, soil-based potting mix. Site in bright indirect light with no direct sun. Tolerant of some shade. Soils should be kept consistently moist, with only a slight reduction in watering from fall to late winter. Prefers high humidity and may appreciate being set on a tray of wet pebbles. Weak fertilizer applications may be made monthly from spring to early fall. Will shed fronds if soils dry out, at which point all fronds may be cut back to about 2” to regenerate. Frond tips may brown up in winter conditions where humidity is low.
Noteworthy Characteristics
Nephrolepis exaltata, commonly called sword fern or Boston fern, is native to Florida, West Indies, Mexico, Central America, South America, Polynesia and Africa. It is an evergreen fern that grows with an upright spreading habit to 3’ tall and as wide. In its native habitat, it may grow to as much as 7’ tall. It is an easy and popular fern to grow indoors. Generally sword-shaped fronds have shallow toothed to entire pinnae. Fronds initially grow upward but arch gracefully with age. A number of different forms are available in commerce including the very popular cultivar 'Bostoniensis' which many years ago earned the reputation of being a classic parlor fern. A number of additional cultivars in commerce feature such variations as curly, wavy, twisted, drooping, double-pinnate and overlapping fronds.
Genus name comes from the Greek words nephros meaning a kidney and lepis meaning a scale.
Specific epithet means very tall or lofty.
Problems
Scale, mealybugs, slugs and white fly may appear. Indoor leaf drop can be bothersome.
Uses
As an indoor fern, it is perhaps best for pedestals or hanging baskets. Locations in or near bathrooms or kitchens may have better humidity. Where winter hardy outdoors, it may be grown in groups or massed in shady areas, or it may be sited at the base of shrubs or around trees.