The lacy tree fern, also known as Cyathea cooperi, is among the largest of the ferns. It is indigenous to the tropical lowlands of Queensland and New South Wales in Australia. The plant derives its name from the delicate nature of its leafy fronds and the fact that grows as a tall, tree-like plant, often resembling a palm tree form. Frequently used as a container plant indoors, lacy tree fern can only be grown outdoors in warm and humid areas.
The trunk of the plant is more narrow than other tree ferns and exhibits distinctive leaf scars where older fronds have died and broken from the trunk. The fronds are bright green and lacy. They are compound, with a central stem, between 1 to 1 1/2 feet in length, and have 12 to 24 leaflets that alternate down either side. Each leaflet is oblong in shape and up to two inches in length. The plant produces no flowers or fruit, reproducing either vegetatively or by spores found under mature fronds.
The plant itself tends to be slow growing, although the fronds can open rather quickly, growing in a spiral pattern around the trunk. The plant grows in clusters of straight, narrow, upright trunks that sprout from rhisomes beneath the ground. In the United States, lacy tree fern can only be grown outdoors or in the most southern portions of Florida and California in the lower parts of hardiness zone 10 and 11.
Lacy tree fern can grow to 18 feet tall and spread as much as six feet across. The fronds radiate outward from the top of the trunk, forming an umbrella shape. As new fronds form, older fronds under the umbrella die and fall away, maintaining the form. The trunk can grow to up to a foot in diameter.
Plant grows exclusively in shade prefers in areas of high humidity. A plan requires a lot of moisture to grow well. Tolerates sandy, loamy ans clay soils, referring fertile soils, rich in organic material, that are well-drained. Propagation is primarily vegetative by taking cuttings from rhizomes or by selling the spores that form on the underside of mature fronds. The trees require little pruning other than assisting the removal of dead or dying fronds.
Lacy tree fern is grown in the United States primarily as an indoor specimen tree in containers, or outdoors in the warmest areas of the country as an ornamental. Because the plant prefers humid environments, it is often grown as a landscape plant around pools, ponds and other water features and around patios and decks where watering is relatively easy.