North America Native Plant

Waialeale Cheesewood

Botanical name: Pittosporum gayanum

USDA symbol: PIGA2

Life cycle: perennial

Habit: shrub

Native status: Native to Hawaii  

Synonyms: Pittosporum gayanum Rock var. skottsbergii Sherff (PIGAS)  âš˜  Pittosporum gayanum Rock var. waialealae (PIGAW)   

Waialeale Cheesewood: A Rare Hawaiian Native Worth Preserving in Your Garden If you’re passionate about Hawaiian native plants and conservation gardening, the Waialeale cheesewood (Pittosporum gayanum) deserves a spot on your must-grow list. This enchanting endemic shrub brings a piece of Kauai’s misty highlands right to your landscape, though finding ...

Rare plant alert!

Region: Conservation status by state

Status: S3: Status is uncertain but is somewhere between the following rankings: Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘

Waialeale Cheesewood: A Rare Hawaiian Native Worth Preserving in Your Garden

If you’re passionate about Hawaiian native plants and conservation gardening, the Waialeale cheesewood (Pittosporum gayanum) deserves a spot on your must-grow list. This enchanting endemic shrub brings a piece of Kauai’s misty highlands right to your landscape, though finding it might require some detective work!

What Makes Waialeale Cheesewood Special

The Waialeale cheesewood is a perennial shrub that typically grows as a multi-stemmed woody plant, usually staying under 13-16 feet tall. What sets this beauty apart is its exclusively Hawaiian heritage – it’s found nowhere else on Earth except the island of Kauai, specifically around the Waialeale area that gives it its common name.

This plant goes by the botanical name Pittosporum gayanum, and you might occasionally see it listed under historical variants like Pittosporum gayanum var. skottsbergii or var. waialealae in older references.

Where You’ll Find This Hawaiian Gem

Pittosporum gayanum is endemic to Hawaii, growing naturally only in the state’s unique island ecosystem. Its extremely limited range makes it a true treasure of Hawaiian biodiversity.

A Beautiful Addition to Your Native Garden

The Waialeale cheesewood offers wonderful aesthetic appeal with its compact shrub form and small, leathery leaves. During blooming season, it produces fragrant white to cream-colored flowers that add both visual interest and a delightful scent to your garden. The flowers are particularly attractive to native Hawaiian insects, making this plant an excellent choice for supporting local pollinators.

Perfect for Naturalistic Hawaiian Landscapes

This versatile shrub works beautifully in several garden settings:

  • Native Hawaiian gardens focused on indigenous species
  • Naturalistic landscapes that mimic Hawaii’s native ecosystems
  • Conservation gardens dedicated to preserving rare plants
  • Understory plantings beneath taller native trees

Growing Conditions and Care

Waialeale cheesewood thrives in USDA hardiness zones 10-11, making it perfect for Hawaii’s tropical climate. Here’s what this mountain native needs to flourish:

  • Soil: Moist, well-draining soils that don’t dry out completely
  • Light: Partial shade to full sun, though it appreciates some protection during the hottest parts of the day
  • Water: Consistent moisture is key – this plant evolved in Hawaii’s misty highland environment
  • Humidity: High humidity levels, which shouldn’t be a problem in most Hawaiian locations

Planting and Care Tips

When growing Waialeale cheesewood, keep these care guidelines in mind:

  • Provide consistent moisture without waterlogging – think of its misty mountain origins
  • Protect from strong winds that can damage its delicate branches
  • Minimal pruning is needed; this shrub naturally maintains a nice shape
  • Mulch around the base to help retain moisture and suppress weeds

Important Conservation Considerations

Here’s something crucial to know: Pittosporum gayanum has a Global Conservation Status of S3, meaning it’s considered vulnerable. With typically only 21-100 occurrences and between 3,000-10,000 individuals remaining, this plant needs our help to survive.

If you choose to grow Waialeale cheesewood, please ensure you source it responsibly. Only purchase plants from reputable native plant nurseries that propagate from legally collected seeds or cuttings. Never collect from wild populations – every plant in nature is precious for this species’ survival.

Wetland Flexibility

One interesting characteristic of this plant is its facultative wetland status in Hawaii, meaning it can handle both wetland and non-wetland conditions. This flexibility makes it adaptable to various moisture levels in your garden, though it generally prefers consistent moisture.

Why Choose Waialeale Cheesewood?

Growing this rare Hawaiian native isn’t just about adding beauty to your landscape – it’s about participating in conservation. Every responsibly grown Waialeale cheesewood in cultivation helps preserve genetic diversity and reduces pressure on wild populations. Plus, you’ll be supporting native Hawaiian ecosystems and the creatures that depend on them.

While this isn’t the easiest native plant to find at your local garden center, the effort to source and grow Waialeale cheesewood pays off with a unique, fragrant, and ecologically valuable addition to your Hawaiian native garden. Just remember: conservation comes first, and responsible sourcing is essential for this vulnerable species.

Waialeale Cheesewood

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Rosales

Family

Pittosporaceae R. Br. - Pittosporum family

Genus

Pittosporum Banks ex Sol. - cheesewood

Species

Pittosporum gayanum Rock - Waialeale cheesewood

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