Nohoanu

Nohoanu: Hawaii’s Critically Endangered Native Geranium

Meet nohoanu (Geranium hillebrandii), one of Hawaii’s most precious and rarest native plants. This endemic Hawaiian geranium is a true botanical treasure that deserves our attention and protection. While you might be familiar with common garden geraniums, this native Hawaiian species is in a league of its own – and sadly, it’s fighting for survival.

What Makes Nohoanu Special

Nohoanu is a perennial shrub that’s native exclusively to the Hawaiian Islands. Unlike its mainland cousins, this unique geranium has adapted to Hawaii’s tropical climate and wet forest environments. The plant typically grows as a multi-stemmed woody shrub, usually staying under 13-16 feet tall, with the characteristic palmate leaves and delicate flowers you’d expect from the geranium family.

You might also see this plant referred to by its synonym, Geranium humile, in older botanical references.

Where Does Nohoanu Grow?

This rare beauty is found only in Hawaii, where it grows naturally in the state’s wet montane forests and volcanic slopes. As an obligate wetland plant, nohoanu almost always occurs in wetland environments, thriving in the consistently moist conditions of Hawaii’s cloud forests.

A Plant in Crisis

Here’s where things get serious: nohoanu is critically imperiled. With a Global Conservation Status of S1, this means there are typically only 5 or fewer known populations, with very few remaining individuals (fewer than 1,000 plants total). In the United States, it’s officially listed as Endangered.

This rarity status means that if you’re interested in growing nohoanu, you have a responsibility to do so ethically and sustainably.

Should You Grow Nohoanu?

The short answer is: only if you can source it responsibly. Given its endangered status, nohoanu should only be grown using plants or seeds obtained through legitimate conservation programs, native plant societies, or botanical institutions working on Hawaiian plant conservation.

Here’s what to consider:

• Never collect plants from the wild – this could contribute to the species’ extinction
• Only purchase from reputable native plant nurseries with proper documentation
• Consider participating in conservation efforts rather than private cultivation
• If you do grow it, treat it as a conservation project, not just a garden plant

Growing Conditions and Care

If you’re fortunate enough to obtain nohoanu through proper channels, here’s what this special plant needs:

• Climate: USDA zones 10-12 only (tropical and subtropical climates)
• Water: Consistent moisture – remember, it’s an obligate wetland plant
• Humidity: High humidity levels similar to Hawaiian cloud forests
• Soil: Well-draining but moisture-retentive, rich organic soil
• Light: Filtered sunlight, similar to understory forest conditions

Garden Design and Landscape Role

Nohoanu is best suited for:

• Specialized native Hawaiian plant gardens
• Conservation collections
• Wetland restoration projects
• Educational botanical displays
• Rain gardens in appropriate climates

Given its shrub growth habit, nohoanu can serve as a unique specimen plant or be integrated into native Hawaiian plant communities alongside other indigenous species.

The Bottom Line

Nohoanu represents both the incredible biodiversity of Hawaii and the urgent need for plant conservation. While most gardeners won’t be able to grow this rare species, learning about it helps us appreciate the unique flora that makes Hawaii special.

If you’re passionate about Hawaiian native plants but can’t access nohoanu, consider supporting Hawaiian plant conservation organizations or growing other native Hawaiian species that are more readily available. Every effort to support native Hawaiian flora helps preserve the islands’ unique botanical heritage.

Remember: with great plants comes great responsibility – especially when they’re as rare and precious as nohoanu.