North America Native Plant

Pacific Treefern

Botanical name: Cyathea lunulata

USDA symbol: CYLU5

Life cycle: perennial

Habit: tree

Native status: Native to Pacific Basin excluding Hawaii  

Synonyms: Alsophila lunulata (G. Forst.) Desv. (ALLU4)  âš˜  Sphaeropteris lunulata (G. Forst.) R.M. Tryon (SPLU)   

Pacific Treefern: A Majestic Native Fern for Tropical Gardens If you’re dreaming of creating your own tropical paradise, the Pacific treefern (Cyathea lunulata) might just be the show-stopping centerpiece you’ve been searching for. This magnificent native fern brings an air of ancient elegance to any garden lucky enough to accommodate ...

Pacific Treefern: A Majestic Native Fern for Tropical Gardens

If you’re dreaming of creating your own tropical paradise, the Pacific treefern (Cyathea lunulata) might just be the show-stopping centerpiece you’ve been searching for. This magnificent native fern brings an air of ancient elegance to any garden lucky enough to accommodate its specific needs.

What Is the Pacific Treefern?

The Pacific treefern, known locally as cheluu in Palau, is a perennial tree fern that can grow into an impressive specimen reaching 13 to 16 feet in height or even taller under ideal conditions. Unlike your typical garden fern, this beauty develops a single trunk that supports a gorgeous umbrella-like canopy of large, graceful fronds.

You might also encounter this fern listed under its former scientific names, Alsophila lunulata or Sphaeropteris lunulata, but Cyathea lunulata is the current accepted botanical name.

Where Does It Come From?

This stunning fern is native to the Pacific Basin, particularly thriving in Guam and Palau. It’s perfectly adapted to the warm, humid conditions of these tropical islands, which gives us important clues about what it needs to flourish in cultivation.

Why Consider Growing Pacific Treefern?

The Pacific treefern offers several compelling reasons to include it in your tropical landscape:

  • Creates dramatic vertical interest as a specimen plant
  • Provides natural shade and canopy structure
  • Adds authentic tropical character to gardens
  • Supports native plant conservation efforts in appropriate regions
  • Low maintenance once established in suitable conditions

Perfect Garden Settings

This tree fern works beautifully in:

  • Tropical and subtropical gardens
  • Shade gardens with high humidity
  • Botanical collections focusing on Pacific flora
  • Protected courtyards and atriums
  • Understory plantings beneath taller trees

Growing Conditions and Climate Requirements

Here’s where things get specific – the Pacific treefern is definitely not a plant for everyone or every climate. This tropical native requires:

  • Climate zones: USDA zones 10-12 only
  • Temperature: Consistently warm conditions with no frost tolerance
  • Humidity: High humidity levels (60% or higher)
  • Light: Partial shade to filtered sunlight
  • Soil: Well-draining but consistently moist, rich organic soil
  • Water: Regular watering to maintain soil moisture

Planting and Care Tips

Successfully growing Pacific treefern requires attention to its native habitat needs:

  • Choose a location protected from strong winds that can damage the large fronds
  • Ensure excellent drainage while maintaining consistent soil moisture
  • Provide regular misting or humidity sources in drier climates
  • Mulch around the base to retain moisture and regulate soil temperature
  • Feed with balanced, slow-release fertilizer during the growing season
  • Remove old or damaged fronds carefully to maintain plant health

Important Considerations

Before falling head-over-heels for this gorgeous fern, consider these factors:

  • It requires very specific tropical conditions and won’t survive in temperate climates
  • Young plants may take several years to develop their characteristic tree-like form
  • As a fern, it won’t provide nectar for pollinators, though it may offer habitat for other wildlife
  • Sourcing can be challenging outside its native range

The Bottom Line

The Pacific treefern is a spectacular choice for gardeners in tropical climates who want to incorporate authentic Pacific island flora into their landscapes. Its dramatic form and native status make it an excellent choice for conservation-minded gardeners in zones 10-12.

However, if you’re gardening outside the tropics, this beauty simply won’t survive your climate. Instead, consider native ferns appropriate to your region that can provide similar structural interest and ecological benefits.

For those lucky enough to garden in suitable tropical conditions, the Pacific treefern rewards patience and proper care with years of stunning, prehistoric elegance that transforms any garden into a living piece of Pacific paradise.

Pacific Treefern

Classification

Group

Fern

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Pteridophyta - Ferns

Subdivision
Class

Filicopsida

Subclass
Order

Polypodiales

Family

Cyatheaceae Kaulf. - Tree Fern family

Genus

Cyathea Sm. - treefern

Species

Cyathea lunulata (G. Forst.) Copel. - Pacific treefern

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA