Nephrolepis exaltata Boston Fern, Sword Fern

Edward F. Gilman, Ryan W. Klein, and Gail Hansen


Introduction

This dependable, easy-to-grow fern produces great masses of long, narrow, pale green leaves, creating beautiful hanging baskets or gently arching out of raised containers. But sword fern also makes a wonderful ground cover, creating a dense, tropical effect, its 2 to 3 foot high, graceful fronds quickly spreading over the ground by means of thin, green runners. While somewhat invasive in ideal locations, sword fern can be controlled by thinning, the removed plants will transplant extremely well. It may be best to confine a grouping of plants with an edging such as plastic or metal to prevent spreading into unwanted areas.

Full Form - Nephrolepis exaltata: Boston Fern, Sword Fern
Figure 1. Full Form - Nephrolepis exaltata: Boston Fern, Sword Fern
Credit: Edward F. Gilman, UF/IFAS

 

Leaf - Nephrolepis exaltata: Boston Fern, Sword Fern
Figure 2. Leaf - Nephrolepis exaltata: Boston Fern, Sword Fern
Credit: Edward F. Gilman, UF/IFAS

General Information

Scientific name: Nephrolepis exaltata

Pronunciation: neff-FRAHL-lepp-piss eck-sahl-TAY-tuh

Common name(s): Boston fern, sword fern, wild Boston fern

Family: Davalliaceae

Plant type: perennial; herbaceous

USDA hardiness zones: 8B through 11 (Figure 3)

Planting month for zone 8: year-round

Planting month for zone 9: year-round

Planting month for zone 10 and 11: year-round

Origin: native to North America

Invasive potential: potentially invasive

Uses: mass planting; container or above-ground planter; naturalizing; hanging basket; suitable for growing indoors

Availability: generally available in many areas within its hardiness range

Shaded area represents potential planting range.
Figure 3. Shaded area represents potential planting range.
Credit:

Description

Height: 0.5 to 4 feet

Spread: depends upon supporting structure

Plant habit: upright

Plant density: moderate

Growth rate: fast

Texture: fine

Foliage

Leaf arrangement: most emerge from the soil, usually without a stem

Leaf type: even-pinnately compound

Leaf margin: serrate; undulate

Leaf shape: lanceolate; ovate

Leaf venation: none, or difficult to see

Leaf type and persistence: semi-evergreen

Leaf blade length: 2 to 4 inches

Leaf color: green

Fall color: no fall color change

Fall characteristic: not showy

Flower

Flower color: no flowers

Flower characteristic: no flowers

Fruit

Fruit shape: no fruit

Fruit length: no fruit

Fruit cover: no fruit

Fruit color: no fruit

Fruit characteristic: no fruit

Trunk and Branches

Trunk/bark/branches: not applicable

Current year stem/twig color: not applicable

Current year stem/twig thickness: not applicable

Culture

Light requirement: plant grows in part shade/part sun; plant grows in the shade

Soil tolerances: occasionally wet; clay; sand; acidic; slightly alkaline; loam

Drought tolerance: moderate

Soil salt tolerances: poor

Plant spacing: 24 to 36 inches

Other

Roots: not applicable

Winter interest: no special winter interest

Outstanding plant: not particularly outstanding

Pest resistance: long-term health usually not affected by pests

Use and Management

Growing in partial to deep shade, sword fern needs moist but well-drained soils until established but can later survive periodic bouts of dry weather. Light fertilizations are recommended during the growing season. Thick clumps can be stimulated by severe pruning, new fronds quickly sprouting from the roots. Plant on 12 to 24 inch centers for quick establishment.

Many cultivars are available for leaf structure, height and growth rate. 'Bostoniensis' is the classic indoor fern, with a spreading and arching growth habit; 'Fluffy Ruffles', 'Rooseveltii', and 'Whitmanii' all have more finely cut and feathery fronds.

Propagation is easily done by division of the clumps.

Pests and Diseases

Sword fern may at times be bothered by scale, mites, mealy bugs, snails, or slugs.

Fungal diseases may occasionally be a problem.