Native Plants

Hawai’i Rockwort

Nototrichium sandwicense

USDA symbol: NOSA

perennial shrub

Hawaii: native

Meet Hawai’i rockwort (Nototrichium sandwicense), also known as kulu`i in Hawaiian – a charming native shrub that’s as resilient as it is beautiful. This woolly-leafed wonder is a true island endemic, meaning it exists nowhere else on Earth except in the Hawaiian Islands. If you’re passionate about native Hawaiian plants ...

Hawai’i Rockwort may be listed as rare in your area.
Global Conservation Status

Status: S3 | Vulnerable: Found only in a restricted range (even if abundant at some locations). Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals.

Hawai’i Rockwort: A Rare Native Gem for Hawaiian Gardens

Meet Hawai’i rockwort (Nototrichium sandwicense), also known as kulu`i in Hawaiian – a charming native shrub that’s as resilient as it is beautiful. This woolly-leafed wonder is a true island endemic, meaning it exists nowhere else on Earth except in the Hawaiian Islands. If you’re passionate about native Hawaiian plants and conservation gardening, this special shrub deserves a spot on your radar.

What Makes Hawai’i Rockwort Special?

This perennial shrub brings a unique silvery-green texture to the garden with its distinctive woolly foliage. The small white to pinkish flowers cluster together in dense arrangements, creating subtle but lovely displays throughout the growing season. As a multi-stemmed woody plant, it typically stays manageable in size, usually growing less than 13-16 feet tall, though most garden specimens remain much smaller.

Where Does It Grow?

Hawai’i rockwort is found exclusively across the Hawaiian Islands, making it a true treasure of Hawaiian biodiversity. This endemic species has adapted perfectly to island conditions over thousands of years.

  • Species observed
  • No observations

Important Conservation Note

Here’s something crucial to know: Hawai’i rockwort is considered vulnerable, with a Global Conservation Status of S3. This means it’s at risk due to its limited range and relatively few populations. While this might sound concerning, it actually makes growing this plant even more meaningful – you’ll be participating in conservation efforts right in your own backyard!

If you choose to grow Hawai’i rockwort, please only purchase from reputable nurseries that propagate plants responsibly rather than collecting from wild populations. This helps protect remaining wild stands while still allowing you to enjoy this remarkable native species.

Perfect Garden Roles

Hawai’i rockwort shines in several garden settings:

  • Rock gardens: Its drought tolerance and compact growth habit make it ideal for rocky, well-draining spots
  • Native Hawaiian landscapes: Essential for authentic island gardens that celebrate local flora
  • Xeriscaping: Once established, it requires minimal supplemental watering
  • Coastal gardens: Naturally adapted to island conditions including salt air

Growing Conditions and Care

The good news is that Hawai’i rockwort is relatively low-maintenance once you understand its preferences:

  • Sunlight: Full sun to partial shade
  • Soil: Well-draining soils are essential – this plant doesn’t tolerate soggy conditions
  • Water: Drought tolerant once established, but avoid overwatering which can lead to root problems
  • Climate: Thrives in USDA zones 10-12, perfect for Hawaiian and similar tropical/subtropical climates

Planting and Care Tips

Getting your Hawai’i rockwort established is straightforward with these guidelines:

  • Plant in well-draining soil – amend heavy clay soils with sand or gravel if needed
  • Water regularly during the first few months until roots establish, then reduce frequency
  • Light pruning helps maintain shape and encourages bushier growth
  • Mulch around the base to retain moisture and suppress weeds, but keep mulch away from the stem

Wildlife and Pollinator Benefits

As a native Hawaiian plant, Hawai’i rockwort has co-evolved with local ecosystems and supports native insects and other small wildlife. The flowers attract various pollinators, contributing to the health of your garden’s ecosystem while supporting Hawaiian biodiversity.

Is Hawai’i Rockwort Right for Your Garden?

If you’re gardening in Hawaii or similar tropical climates and want to grow plants that truly belong to the landscape, Hawai’i rockwort is an excellent choice. Its low water needs, attractive appearance, and conservation value make it a win-win for environmentally conscious gardeners.

Just remember the golden rule: always source your plants responsibly from nurseries that propagate rather than wild-collect. By choosing Hawai’i rockwort, you’re not just adding a beautiful native to your garden – you’re helping preserve a piece of Hawaiian natural heritage for future generations.

Nototrichium sandwicense is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Nototrichium sandwicense is also known as:

Nototrichium sandwicense var. decipiens | USDA symbol: NOSAD
Nototrichium sandwicense var. dubium | USDA symbol: NOSAD2
Nototrichium sandwicense var. forbesii | USDA symbol: NOSAF
Nototrichium sandwicense var. helleri | USDA symbol: NOSAH
Nototrichium sandwicense var. kolekolense | USDA symbol: NOSAK
Nototrichium sandwicense var. kauaiense | USDA symbol: NOSAK2
Nototrichium sandwicense var. leptopodum & | USDA symbol: NOSAL
Nototrichium sandwicense var. longispicatum | USDA symbol: NOSAL2
Nototrichium sandwicense var. lanaiense | USDA symbol: NOSAL3
Nototrichium sandwicense var. lanceolatum | USDA symbol: NOSAL4

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Caryophyllidae
Order: Caryophyllales
Family: Amaranthaceae Martinov - Amaranth family
Genus: Nototrichium (A. Gray) Hillebr. - rockwort

Species: Nototrichium sandwicense (A. Gray) Hillebr. - Hawai'i rockwort

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