Australian tree fern (Cyathea cooperi or Sphaeropteris cooperi) is an extremely large fern that can reach 15 to 30 feet tall, with leaves up to 18 inches long and a trunk diameter of 12 inches. This unique member of the Cyatheaceae family is hardy in USDA zones 10B through 11. According to the University of Florida Extension, it is an excellent specimen in a shade garden and is often planted around a shaded pool or small pond for the double image created on the water.
Plant your Australian tree fern in a well-drained, sandy or loam soil. Amend the soil, if needed, with compost to make it fertile. Australian tree fern prefers partial to full shade.
Keep your fern's soil evenly moist. Do not let the soil dry out beyond the top inch. Water more frequently during dry conditions, and water in the early morning so that the water does not evaporate quickly.
Fertilize with organic fertilizers and well-rotted animal manure, according to the Australian National Botanic Gardens. Most ferns do not need heavy applications of fertilizer.
Propagate your Australian tree fern by removing the spores found on the underside of mature leaves and placing them on the ground. They do not need to be covered with soil.