Native Plants

Forest Gardenia

Gardenia brighamii brighamii

USDA symbol: GABR

perennial shrub

Hawaii: native

If you’re passionate about native Hawaiian plants, you’ve probably heard whispers about the forest gardenia (Gardenia brighamii brighamii), also known as nanu in Hawaiian. This isn’t your typical backyard gardenia – it’s one of Hawaii’s most precious and endangered native shrubs, making it both a gardening dream and a conservation ...

Forest Gardenia may be listed as rare in your area.
Global Conservation Status

Status: S1 | Critically imperiled: Typically 5 or fewer occurrences or under 1,000 remaining individuals.

Hawaii

Status: Endangered | Endangered. In danger of extinction throughout all or a significant portion of its range.

Forest Gardenia: Hawaii’s Rare Native Treasure Worth Protecting

If you’re passionate about native Hawaiian plants, you’ve probably heard whispers about the forest gardenia (Gardenia brighamii brighamii), also known as nanu in Hawaiian. This isn’t your typical backyard gardenia – it’s one of Hawaii’s most precious and endangered native shrubs, making it both a gardening dream and a conservation priority.

A Plant on the Edge of Extinction

Here’s the reality check every gardener needs to hear: the forest gardenia is critically endangered. With a Global Conservation Status of S1 (Critically Imperiled) and listed as Endangered in Hawaii, this species typically has fewer than 1,000 individuals remaining in the wild. When we talk about rare plants, this one takes the cake – or should we say, takes the lei?

Important: If you’re considering adding this plant to your garden, you must source it responsibly from authorized conservation programs or certified nurseries. Never collect from wild populations.

Where Forest Gardenia Calls Home

This remarkable shrub is endemic to Hawaii, meaning it exists nowhere else on Earth naturally. You’ll find it growing exclusively in the Hawaiian Islands, where it once thrived in native forests before habitat loss and other threats pushed it to the brink.

  • Species observed
  • No observations

What Makes Forest Gardenia Special

As a perennial woody shrub, the forest gardenia typically grows as a multi-stemmed plant reaching up to 13-16 feet in height, though it can sometimes grow taller or develop a single stem depending on conditions. Like its more common gardenia cousins, it likely produces those signature white, fragrant flowers that make gardenias so beloved – though with the added significance of being a unique Hawaiian treasure.

Growing Conditions and Care

If you’re fortunate enough to obtain forest gardenia through proper conservation channels, here’s what this tropical beauty needs:

  • Climate: USDA hardiness zones 10-11 only (tropical conditions required)
  • Soil: Well-draining soil that mimics its native forest habitat
  • Light: Partial shade to full sun, depending on your specific microclimate
  • Water: Consistent moisture without waterlogging
  • Special care: Given its endangered status, consider working with local botanical gardens or conservation groups for guidance

A Garden with Purpose

Forest gardenia isn’t just another pretty face in the garden – it’s a living piece of Hawaiian heritage. This plant works beautifully in:

  • Native Hawaiian landscape designs
  • Conservation gardens focused on endangered species
  • Educational botanical collections
  • Restoration projects (when part of official programs)

While we don’t have complete data on its specific wildlife benefits, native Hawaiian plants typically support native pollinators and other island fauna that have co-evolved with them over millennia.

The Bottom Line for Gardeners

Should you plant forest gardenia? If you can source it responsibly and you’re in the right tropical climate, absolutely – but with a conservation mindset. This isn’t about having a rare plant to show off; it’s about participating in the preservation of Hawaii’s unique botanical heritage.

For most mainland gardeners, consider supporting forest gardenia conservation efforts instead, and opt for other native gardenias appropriate to your region. If you’re in Hawaii, reach out to local native plant societies, botanical gardens, or conservation organizations to learn about legitimate ways to help preserve this species.

Remember: every forest gardenia grown in a responsible conservation setting is a small victory against extinction. Now that’s what we call gardening with purpose!

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Asteridae
Order: Rubiales
Family: Rubiaceae Juss. - Madder family
Genus: Gardenia Ellis - gardenia

Species: Gardenia brighamii Gardenia brighamii - forest gardenia

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