Dicksonia antarctica - L

About the Dicksonia antarctica - L

Dicksonia antarctica, also known as the Tasmanian tree fern, is a slow-growing tree fern that develops a sturdy, fibrous trunk and a broad crown of gracefully arching, dark green fronds when mature. The species is naturally evergreen but may temporarily lose its fronds in a cold climate. In size L, this tree fern is suitable for a sheltered position in the garden or a large container; the retail size alone provides no information about its age or trunk height.

Characteristics

Origin: Dicksonia antarctica is native to south-eastern Australia, from south-eastern Queensland through New South Wales and Victoria to Tasmania. It grows mainly in moist, cool forests, mountain gullies and along streams.

Family: This tree fern belongs to the tree fern family, Dicksoniaceae.

Position: Outdoors, choose a sheltered position in partial or full shade, preferably protected from drying winds. Cultivation in a large container is possible and makes winter protection easier. Under glass, a cool, shaded, humid and well-ventilated environment is suitable; a warm, dry living room is less appropriate.

Height: In cultivation, a mature specimen generally reaches approximately 2.5 to 4 metres in height and spread. Very old plants can become considerably larger in their natural habitat. Its ultimate size will usually remain more restricted in a container.

Flowering period: Not applicable, because Dicksonia antarctica does not produce flowers. Sufficiently developed plants may form spores on the undersides of mature fronds; the species does not produce fruit.

Flower colour: Not applicable; ferns do not produce flowers.

Hardiness: An established specimen in a sheltered position tolerates light frost, but temperatures below approximately -5°C can cause serious damage. Protect the crown and trunk during frost and preferably overwinter a container-grown plant in a sheltered, frost-free place, because the root ball freezes more quickly in a pot.

Soil type: Use a humus-rich, airy and moisture-retentive growing medium that drains excess water well. Acidic to neutral soil is suitable. A layer of mulch helps keep the root zone evenly moist.

Care

Light: Provide filtered light, partial shade or full shade. Protect the plant from strong midday sun, especially where the air or soil dries quickly.

Water: Keep the growing medium evenly moist during active growth and prevent prolonged drying. In warm or dry weather, regularly wet the fibrous trunk as well, but do not allow water to stand around the roots and do not keep the crown continuously wet in winter.

Fertiliser: During active growth, regularly apply a modest dose of a suitable fern fertiliser according to the instructions on the packaging. Avoid high doses and reduce feeding when growth stops during the cold season.

Pruning: Remove only completely dead or clearly damaged fronds and cut them carefully close to the trunk. Do not damage the central growing point in the crown.

Repotting: Preferably repot a container-grown plant in spring when the pot is well filled with roots. Choose a stable pot that is only slightly larger, with ample drainage holes, and position the plant at the same depth as before. For large specimens, renewing the top layer may be sufficient.

Humidity: High humidity supports healthy fronds and limits drying. Under glass, combine this with good ventilation and avoid dry air and persistent heat.

Special features: The trunk formed by the species at maturity is botanically an upright rhizome densely covered with fibrous roots. Large, arching fronds develop from the crown. The trunk grows only slowly. The starch-rich pith has traditionally been used as food, but extracting it severely damages the trunk; the specimen offered is an ornamental plant and is not intended for consumption.