Students for Stewardship The Cork Board
← Back to the library

Great Fern

Diplazium expansum (dy-PLAY-zee-um EX-pan-sum)

Family: Aspleniaceae Unknown Herbaceous

Great fern is a large perennial plant in the spleenwort family (Aspleniaceae). Its origin is Mexico, Central America, northern South America and islands in the Caribbean. The great fern has an erect growth habit and may grow up to 5 feet tall. It is found along stream banks, rocky ravines and glades at high elevations. This plant thrives in bright, indirect light and shady location. Harsh afternoon sun should be avoided. The soil recommended should be moist, well-drained, high in organic matter, and acidic. Water the plant at the base, avoid getting the foliage wet, and use distilled water or rainwater to prevent mineral build up. This fern should be watered any time the soil feels dry. A warm humid environment and temperatures between 60 degrees and 77 degrees are needed for optimal growth. Temperatures below 50 or above 86 degrees are not well tolerated. Keep the plant tidy by removing any damaged, diseased, or dead fronds. Pruning is recommended in the spring or early summer. This plant can be propagated by spores, rhizomes, cuttings, or division. The great fern has fronds that are large, bright green, shiny, erect, lance-shaped, and arching. They can grow up to 5 feet long and 10 inches wide. The spores are located on the underside of the fronds. This fern is not hardy outside the tropics and must be grown as an ornamental houseplant or conservatory subject here in North Carolina. Insects, Diseases, and Other Plant Problems: Monitor for spider mites and mealybugs. Potential diseases include leaf spot and rust. Soggy wet soils can result in root rot, and direct sunlight can damage the fronds. VIDEO Created by NC State Extension's Homegrown series featuring Mark Weathington , Director of JC Raulston Arboretum .

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 44 attributes.

How it fits the guild

Guild layer 4 - Herbaceous Optimal soil pH Acid (<6.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Often confused with Davallia fejeensis
Fills a similar niche Lonicera ligustrina var. yunnanensis Monarda 'Raspberry Wine' Sphaeropteris cooperi

Full plant profile

Growing Conditions
Plant type
Fern; Herbaceous Perennial; Houseplant
Life cycle
Perennial
USDA zones
9a, 9b, 10a, 10b, 11a, 11b
Light
Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
High Organic Matter; Loam (Silt); Sand
Soil pH
Acid (<6.0)
Soil drainage
Good Drainage | Moist
Available space
3 feet-6 feet
Growth rate
Rapid
Maintenance
Medium
Canopy layer
4 - Herbaceous
Form & Appearance
Habit / form
Arching; Erect
Texture
Medium
Foliage
Broadleaf Evergreen
Leaf color
Green
Leaf type
Compound (Pinnately , Bipinnately, Palmately); Fronds
Leaf arrangement
Alternate
Leaf shape
Deltoid; Ovate
Leaf margin
Crenulate; Entire
Leaf feel
Glossy
Leaf value
Showy
Leaf size
> 6 inches long, > 6 inches wide
Hairs present
Yes
Leaf detail
Green fronds are up to 38 inches long with 8 to12 pairs of pinnules (leaflets) that are alternate to sub-alternate and may or may not be stalked. The margins may be crenulate to entire. The sori are light brown and on the undersides of the fronds.
Flower detail
No flowers.
Fruit detail
No fruits. This plants reproduces via spores.
Wildlife & Ecology
Native status
Unknown
Origin
Mexico to Guyana and Peru
Distribution
Native: Bolivia, Colombia, Costa Rica, Cuba, Ecuador, Guatemala, Guyana, Haiti, Honduras, Jamaica, Mexico Central, Mexico Gulf, Mexico Southwest, Nicaragua, Peru, Puerto Rico, Venezuela, and the Windward Islands.
Food & Medicine

Uses (ethnobotany)

The rhizomes are used as a medicine for the treatment of skin infections, toothaches, rheumatism, and for pain relief. It is also used for food and environmental purposes.

Landscape Use
Landscape location
Container; Houseplants; Riparian; Woodland
Landscape theme
Shade Garden; Water Garden
Garden tags
#fern #deer resistant #evergreen ferns #partial shade tolerant #stream banks #woodland #houseplant #herbaceous perennial #fast growing #acidic soils tolerant #container plant #pond #th-touch
Problems & Resistance
Resistant to
Deer
Particularly resistant to
Deer
Propagation
Division

Planted at Hunnicutt

Nobody’s planted this one yet.