Alsophila Species, Ponga, Silver Tree Fern

Alsophila dealbata

Family: Cyatheaceae
Genus: Alsophila (al-so-FY-la) (Info)
Species: dealbata (day-al-BAH-tuh) (Info)
Synonym:Cyathea dealbata




Water Requirements:

Unknown - Tell us

Sun Exposure:

Partial to Full Shade


Grown for foliage


Foliage Color:




8-10 ft. (2.4-3 m)

10-12 ft. (3-3.6 m)

12-15 ft. (3.6-4.7 m)

15-20 ft. (4.7-6 m)

20-30 ft. (6-9 m)


20-30 ft. (6-9 m)


USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

Where to Grow:

Unknown - Tell us



Bloom Color:


Bloom Characteristics:

Unknown - Tell us

Bloom Size:

Unknown - Tell us

Bloom Time:


Other details:

Soil pH requirements:

5.1 to 5.5 (strongly acidic)

Patent Information:


Propagation Methods:

From spores

Seed Collecting:

N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed


This plant is said to grow outdoors in the following regions:

Mckinleyville, California

Fort Lauderdale, Florida

Palm Harbor, Florida

Sarasota, Florida

Summerfield, Florida

Ambler, Pennsylvania

Woodland, Washington

show all

Gardeners' Notes:


On Dec 5, 2016, Lt35phila from Ambler, PA wrote:

I have grown this tree fern for ten years in a large pot. It is over 6 feet tall. It must be kept moist. It sits in a tray of water and I feed it with organic fertilizer. In the summer it's in full sun and in the winter it's in an unheated basement under a fluorescent light. It's a tough plant. I live in the Philadelphia area.


On Feb 6, 2012, bikerlady from Summerfield, FL wrote:

Have grown this plant in South Florida where it flourished year long, and lately in Central Florida where it can sometimes go into freezing weather. I have covered the plant and have also left it uncovered during those freezing periods. The result seems to be the same. It has been beaten back with fronds turning brown, but it has survived and continued to grow from a little thing when I planted it six years ago, to over six feet tall, and it reaches this height every year, no matter what kind of beating it gets in the winter. It gets full sun every day and is somewhat protected by being planted up into an angle of the house. I believe Summerfield FL is zone 8. It is one of the most beautiful plants I have ever had in my gardens.


On Feb 6, 2012, aulani61 from Emporia, KS wrote:

These beautiful tree ferns grow well in Hawaii. I know people on the Big Island who use them as a natural greenhouse for their commercial anthurium growing operation. Beneath twin rows of these ferns grow the anthuriums of every color and variety. Genius!


On Aug 14, 2009, mattycindy from Christchurch,
New Zealand wrote:

This tree fern is easily recognized by its distinctive silvery underside of the frond. Young plants are however green underneath.
It is found throughout New Zealand in lowland to montane forests.

It is easily grown and will tolerate drier conditions than the other tree ferns. Does best in a sheltered site with shade or semi shade and good moist, well-composted soil is best. Suitable for growing in a large pot too.


On Jun 21, 2007, Cretaceous from El Sobrante, CA (Zone 9b) wrote:

Native to New Zealand.

Cyathea are listed on CITES Appendix II.


On Sep 24, 2005, BayAreaTropics from Hayward, CA wrote:

PBS had a documentary about these regal ferns planted on an island off the coast of Ireland. They were said to be over a century old.....


On May 25, 2005, koolkatken from Auckland,
New Zealand wrote:

Beautiful addition to a tropical look. Does not like lots of sun and needs plenty of water. Great for the shady, damp areas of the house where you don't know what to put there.


On Sep 9, 2003, kennedyh from Churchill, Victoria,
Australia (Zone 10a) wrote:

This is a New Zealand tree-fern, growing commonly all over New Zealand, mostly on dry forested hillsides. The fronds are silvery on the under surface and give rise to one of the emblems of New Zealand, the silver fern.