Native Plants

Blue Lawngrass

Garnotia stricta

USDA symbol: GAST3

perennial grass

Hawaii: non-native, naturalized
Pacific Basin excluding Hawaii: native

Meet blue lawngrass (Garnotia stricta), a tough little perennial grass that’s made itself at home in Hawaii and other Pacific islands. While it might not be the showiest plant in your garden, this unassuming grass has some qualities that might surprise you – and a few considerations you should know ...

Blue Lawngrass: A Hardy Pacific Grass for Low-Maintenance Landscapes

Meet blue lawngrass (Garnotia stricta), a tough little perennial grass that’s made itself at home in Hawaii and other Pacific islands. While it might not be the showiest plant in your garden, this unassuming grass has some qualities that might surprise you – and a few considerations you should know about before deciding if it’s right for your landscape.

What Exactly Is Blue Lawngrass?

Blue lawngrass is a perennial grass that forms dense tufts of narrow, blue-green foliage. Don’t let the name fool you – it’s not actually blue, but rather has a subtle blue-green tint that gives it its common name. You might also see it listed under its scientific synonyms Garnotia acutigluma or Garnotia sandwicensis in older references.

This grass belongs to the graminoid family, which is just a fancy way of saying it’s part of the grass and grass-like plant group. It produces delicate seed heads that sway gently in ocean breezes – a characteristic that makes it quite at home in coastal environments.

Where Does Blue Lawngrass Come From?

Here’s where things get interesting from a native gardening perspective. Blue lawngrass is native to the Pacific Basin, but not to Hawaii. It’s originally from places like the Philippines and Indonesia, but has naturalized in Hawaii, Guam, and Palau, where it now reproduces spontaneously without human help.

  • Species observed
  • No observations

In Hawaii, this grass has established itself so well that it’s considered naturalized – it’s not going anywhere anytime soon. While it’s not native to the islands, it’s also not currently listed as invasive, putting it in that gray area that many gardeners face when choosing plants.

Why You Might (Or Might Not) Want Blue Lawngrass

Reasons to consider it:

  • Extremely low maintenance once established
  • Drought tolerant after establishment
  • Good for erosion control on slopes
  • Tolerates coastal conditions well
  • Can handle both wetlands and drier areas (it’s classified as facultative for wetland status)
  • Thrives in USDA hardiness zones 9-11

Reasons to think twice:

  • Not native to Hawaii (or most places it’s now found)
  • Limited wildlife and pollinator benefits
  • Can spread via seeds, potentially crowding out native plants
  • Not particularly ornamental or eye-catching

Growing Blue Lawngrass Successfully

If you decide blue lawngrass fits your landscape goals, you’ll find it refreshingly easy to grow. This grass isn’t picky about conditions – it can handle everything from full sun to partial shade and adapts to various soil types as long as drainage is decent.

Planting tips:

  • Plant in well-draining soil
  • Choose a spot with full sun to partial shade
  • Space plants appropriately as they’ll spread over time
  • Water regularly until established, then reduce watering

Care requirements:

  • Minimal fertilization needed
  • Drought tolerant once established
  • May self-seed in favorable conditions
  • Occasional trimming to maintain appearance

The Native Alternative Consideration

Since blue lawngrass isn’t native to Hawaii, you might want to consider native grass alternatives that provide similar benefits while supporting local ecosystems. Native Hawaiian grasses and sedges can offer comparable erosion control and low-maintenance qualities while providing better habitat for native wildlife.

Some native alternatives to research include indigenous Hawaiian sedges and grasses that are naturally adapted to your specific island’s conditions.

The Bottom Line

Blue lawngrass is a hardy, low-maintenance option for gardeners who need a tough grass for challenging sites. While it’s not native to Hawaii, it’s not currently considered invasive either. If you choose to plant it, just be mindful of its potential to spread and consider incorporating native plants elsewhere in your landscape to support local ecosystems.

Remember, the best plant for your garden is one that meets your needs while fitting responsibly into your local environment. Blue lawngrass might just be that plant – or it might inspire you to explore native alternatives that offer similar benefits with greater ecological value.

Garnotia stricta 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. Garnotia stricta is also known as:

Garnotia acutigluma | USDA symbol: GAAC
Garnotia sandwicensis | USDA symbol: GASA3

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.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" — matching plants to their ideal growing conditions, so they'll thrive with less care and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection can be if you don't have the right information. While tags on nursery plants list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. You might be surprised to learn that popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. The table below gives insight into the preferred growing conditions of this plant throughout its geographical distribution.

Region
Preferred Habitat

Hawaii ()

Facultative
Wetland Glossary
Obligate Wetland
Facultative Wetland
Facultative
Facultative Upland
Obligate Upland
Almost always occurs in wetlands
Usually occurs in wetlands but may occur in non-wetlands
Can occur in wetlands and non-wetlands
Usually occurs in non-wetlands but may occur in wetlands
Almost never occurs in wetlands

Classification

Group: Monocot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Liliopsida - Monocotyledons
Subclass: Commelinidae
Order: Cyperales
Family: Poaceae Barnhart - Grass family
Genus: Garnotia Brongn. - lawngrass

Species: Garnotia stricta Brongn. - blue lawngrass

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