Sphaeropteris Species, Norfolk Island Tree Fern, Norfolk Tree Fern, Smooth Tree Fern

Cyathea brownii is reputed to be the largest living species of tree fern, and can attain a height of over 40 feet.

It is l...Read Moreisted in the 1997 IUCN Red List of Threatened Plants as vulnerable.

Available from Thimble Farms, B.C., Canada.

Cyathea are listed on CITES Appendix II.

It is also a much darker green than the Australian tree fern when grown in light shade. Hard to find..got mine at a botanical garden sale...Read More. It has grown from a seedling (frondling?) to 6 foot spread in 4 years-and only two of those in ground. And it does like fertilizer more than the common tree ferns.Yet,still does not develop the massive trunk as it does in it's natural habitat. And i have noticed that for a large fern it has a tendency to only send up only one frond at a time.
EDIT: Sailed through the 07 freeze. It even threw out a frond or two over the winter-well,the second frond is still a crozier. But,I'm not so sure i would call it a fast growing tree fern.
EDIT2: After a slowing down period it has taken off again. Even the crown seems to be too large for the trunk to hold up..I understand that is a result of low humidity and fast growth.Hey,it's a living thing making its own rules...
2008: This fern continues to ad bulk and now shows the crown of fronds of an adult C.brownii. That is,unlike most other Cyatheas, C.brownii fronds are held up right in a vase shape much like the Dicksonia's.In coastal areas and coastal valleys it may be capable of ,maybe prefer, full sun. It's a big fern.
How this can be confused with C.cooperia or even be said to be a variant of cooperi is a wonder. They look nothing alike.
2018: I nearly lost this fern in the drought years. Then,3 years ago I dug it up and put in a large pot with peat potting soils and it was a slow but steady recovery..its now growing fast again and I might replant one day back in ground..for now though its glossy green fronds stand out as un C.cooperi like.
A great fern,different.

For those who love tree ferns, but can't wait for your Australian tree fern to get to any size, or shade your yard, this is the fern for ...Read Moreyou (one of several). This is 3x as fast a grower, and larger and better looking than an Australian tree fern (Cyathea cooperi), except for the Brentwood variety- that one is faster and larger still. This has a darker trunk and slightly more sun tolerance. However, full sun is only recommended in moderately cooler climates. Blazing heat, like seen inland in Southern California, will toast any tree fern. Then shade is recommended.