The Australian fern tree is so perfect for extreme Southeastern United States gardeners. In fact, it's the only tree fern that is commonly grown in South Florida. This beauty is cold hardy to 23 degrees F, but leaf damage begins occurring before that. So if your neighborhood is naturally hot and wet year-round, this is the plant for you. Australian tree ferns will thrive well in USDA Zone 10 as long as they are planted in proper sites and provided adequate food and water. Treat them as the rainforest natives that they are.
Plant the Australian tree fern in a fertile, shady or partially shaded spot with sandy soil and excellent drainage. Mix into the soil 25 to 50 percent of well-rotted manure, humus or any organic compost on hand.
Plant the Australian tree fern with 1/3 of its trunk below the surface of the soil. Apply a seaweed fertilizer according to the packaging instructions. Apply enough water to let the fertilizer absorb into the soil.
Mulch with 2 to 3 inches of leaf mold, dried leaves or pine bark.
Water the Australian tree fern so that the planting site is evenly moist but not soggy in the early morning during the growing season. Don't allow it to completely dry out or it will wither.
Water the foliage and trunk as well as its roots to provide necessary humidity. Give the trunk and the crown of fronds a good, refreshing soak when the soil is watered and anytime during the growing season that rainfall is scarce.
Feed the Australian tree fern seaweed fertilizer three months after planting. Follow with maintenance feedings every three months thereafter throughout the year. Follow the manufacturer's instructions carefully.
Prune fronds from the Australian fern tree only when they've turned completely brown. Even dying fronds can supply nutrients to an otherwise healthy plant.