Dicksonia fibrosa - New Zealand Tree Fern

Dicksonia fibrosa is a tree fern that, at maturity, forms a black trunk called a stipe, with a large tuft of lush beautiful emerald green leaves giving it a strong exotic character.

In nature, the trunk (stipe) of this fern can reach up to 6m (19 ft 8 in) in height and measure 30 to 50cm (11.8 to 19.7 in) in diameter. In our climate, it rarely exceeds 2 to 3 meters (6 feet 7 inches to 9 feet 10 inches) in height. It is made up of brown bristles and a dense network of capillary roots that give it its black colour and fibrous appearance. Its growth is slow, but its lifespan is extremely long.

The fronds (leaves) appear at the end of the trunk and measure from 1m (3 ft 4 in) to 2m (6 ft 7 in) in length, forming a wide, spreading tuft that can measure up to 4m (13 ft 1 in) in diameter. Dark green in colour, the tripinnate fronds are rough to the touch and have a very matte appearance. They are evergreen and each has an average lifespan of 2 years unless exposed to severe frost when they 'burn' in winter and are replaced by new fronds the following spring.

Tree ferns are not known for their great hardiness, however, some species, notably Dicksonia antartica and D. fibrosa, are quite hardy without any protection down to -7C°, and even down to -10C° if they are in a sheltered location, without wind.

Beyond that winter protection is necessary. It can be as simple as a 'straw hat' to protect the future fronds at the top of the trunk, the most sensitive area to cold. With this protection, the fern can withstand temperatures down to about -12°C (10.4 °F) for a short period. Another solution is to grow them in a large pot and bring them indoors in winter to a frost-free or minimally heated conservatory.

Similar in appearance to the Dicksonia antartica, D. fibrosa has a smaller and darker trunk and foliage. Both species can be acclimatised in our climate.