Lacy Tree Fern Sphaeropteris cooperi

The Australian tree fern is a medium to large, fast-growing, ornamental, tropical, evergreen fern that is native to New South Wales and Queensland, Australia. It can reach the height of 15 to 25 feet tall and 10 to 12 feet wide, but up to 50 feet tall in the wild. Its form resembles a martini glass with gracefully arching fronds emerging from a skinny trunk. It has a single, scale covered trunk and long, lacy, feathery, green, bipinnately compound fronds. This tree is a member of the scaly tree fern family (Cyatheaceae).

This tree prefers partial to full shade and moist, well-drained, loamy, sandy soil. The soil should be kept moist consistently, and it also requires a warm and humid environment with temperatures ranging from 65 to 80 degrees Fahrenheit. It is propagated by spores.

The bark of this fern is brown, fibrous, and there are oval leaf scars encircling the trunk. The fronds are delicate, medium-green, bipinnately compounded, and can reach up 13 to 20 feet in length. The stipes or stems of the fronds will fall off when the fronds die, leaving oval scars on the brown scaly stems. Young fronds are known as fiddleheads and have stiff white hairs. The brown sori appear in a single row on the undersides of the leaflets, close to the midrib.

The Australian tree fern is easy to grow and is often used gardens or public areas. In climates such as North Carolina, it may be used as a tropical container specimen seasonally on a patio or deck. If grown indoors, it will require a bright and humid location such as a sunroom or bathroom. This tropical plant may grow to tall as an indoor plant and may be best reserved for conservatories or greenhouses.   

Insects, Diseases, and Other Plant Problems:  Monitor for spider mites and mealybugs. It is usually resistant to diseases. Root rot can occur from watering the crown; therefore, it is best water at the base of the trunk. Rapid changes in temperature or humidity can cause browning of the fronds. 

This tree has naturalized in some forests in Hawaii and is considered invasive. This tree has weedy tendencies.

VIDEO Created by NC State Extension's Homegrown series featuring Mark Weathington, Director of JC Raulston Arboretum.