Nephrolepis exaltata

 

Description

Wild Boston fern has erect fronds up to 3' long and 6" wide in tufted clusters arising from underground stems called rhizomes. The individual pinnae (leaflets) are as much as 3" long and shallowly toothed, but not further divided. The round sori (clusters of spore-bearing organs) are in two rows near the margins on the underside of the pinnae.

There are dozens of cultivars of this species. Some of the more popular selections include 'Rooseveltii plumosa' and 'Fluffy ruffles' which have pinnae that are deeply incised and feathery on the tips. 'Bostoniensis' (Boston fern) has broader fronds that arch gracefully downward and probably is the most tolerant of indoor conditions. There is also 'Golden Boston' which has yellow fronds, 'Hillii' which has doubly pinnate fronds, 'Childsii' which has broad 3 or 4 pinnate, overlapping fronds and 'Verona' has very drooping, 3 or 4 pinnate fronds.

Location

Boston fern, Nephrolepis exaltata, is a common native fern in humid forests and swamps in Florida, and occurs also as a native in South America, Mexico and Central America, the West Indies, Polynesia and Africa - a testament to the ability of wind to disperse tiny spores! Boston fern often grows on the trunks of cabbage palms. Some of the selected cultivars have escaped and established in Florida.

Culture

Light: Partial shade to shady outdoors and bright, filtered light indoors. Moisture: Boston fern likes a moist but not soggy, soil, rich in organic matter. This is the most drought tolerant of the commonly cultivated ferns, but it thrives only under conditions of high humidity. In containers, put a couple inches of pebbles beneath the potting medium and keep them (but not the potting medium itself) wet to increase humidity. Mist Boston fern every day or so if the relative humidity is below about 80%. Hardiness: USDA Zones 9 - 11. Boston fern is killed to the ground by frost but will re-emerge in spring. Propagation: By division of rooted runners. The various cultivars will not come true from spores.

Outdoors, Boston fern is usually grown in moist, shady sites beneath ornamental trees or shrubs, or as a ground cover. It makes a good ground cover for the north side of the house or under shade trees where little else will grow. Under favorable conditions, Boston fern will spread by underground runners. Indoors, the species and its many cultivars are often grown in hanging baskets or on pedestals. They are especially suitable for the bathroom or kitchen where they will appreciate the high humidity.

Features

Boston fern and its cultivars are the toughest and most widely used of all ferns. They were the typical "parlor ferns" before the advent of central heat and air. Even today they can survive for a year or two in centrally heated homes, and still look pretty good.

Some authorities place Nephrolepis in the family Davalliaceae (Davallia family), others in the Polypodiaceae (polypody family), and still others in the Oleandraceae (ladder fern family).