Cyathea medullaris - M

About the Cyathea medullaris - M

Cyathea medullaris, botanically accepted as Sphaeropteris medullaris, is an evergreen tree fern from New Zealand and several islands in the South Pacific. At maturity, the species develops an upright, dark trunk topped by a crown of large green fronds that arch upwards. Size M refers solely to the commercial size and provides no information about the plant's age, maturity or whether these mature features are already visible.

Characteristics

Origin: This tree fern is native to New Zealand, the Chatham Islands, Fiji, Vanuatu, the Marquesas Islands, the Society Islands, the Tubuai Islands and Pitcairn. In New Zealand, the species grows mainly in lowland forest and moist coastal forest.

Family: Cyatheaceae.

Position: A sheltered position in partial shade or bright, filtered light. In the Netherlands, container cultivation is practical: during warm periods the plant can be placed outdoors in a sheltered position and before winter it should be moved to a bright, frost-free greenhouse, conservatory or similar space.

Height: In the wild, this tree fern can develop a trunk approximately 20 metres tall and fronds up to around 5 metres long. The plant generally remains considerably smaller in a container.

Flowering period: Not applicable. As a fern, this species does not produce flowers; fertile fronds may carry spores.

Flower colour: Not applicable; this tree fern does not produce flowers.

Hardiness: Limited hardiness. Mature, well-established specimens may tolerate light frost in very mild, sheltered locations, but a plant in size M or in a container is more vulnerable. Protect the plant from frost and overwinter it in a frost-free location.

Soil type: A humus-rich, airy and well-drained potting mix that can remain evenly moist without becoming waterlogged. Slightly acidic to neutral soil is suitable.

Care

Light: Place the plant in partial shade or bright, filtered light. Avoid strong midday sun, especially behind glass, as this can damage the fronds.

Water: Keep the potting mix evenly moist and do not allow the root ball to dry out completely. Provide additional water during warm, dry periods and always allow excess water to drain freely. Avoid prolonged stagnant moisture around the roots.

Fertiliser: During the active growing period, regularly apply a low dose of fertiliser for ferns or foliage plants. Reduce feeding when growth slows.

Pruning: Remove only completely dried or damaged fronds. Always leave the growing point in the centre of the crown intact.

Repotting: Repot when the roots have filled the container. Use a pot one size larger with sufficient drainage holes and disturb the roots as little as possible.

Humidity: Elevated humidity supports healthy frond development. Avoid dry air from heating systems while maintaining some air circulation around the plant.

Special features: Mature specimens develop a striking dark to black trunk with distinctive hexagonal leaf scars and dark frond stalks. Clusters of spores form on the underside of fertile fronds; these mature features may not yet be visible in size M. The trunk pith, bases of the frond stalks and still-coiled young fronds were traditionally eaten after preparation. This ethnobotanical use is not a consumption recommendation; use plant parts only after expert species identification and correct preparation, and harvesting the trunk pith destroys the plant.