North America Non-native Plant

Dwarf Eelgrass

Botanical name: Nanozostera japonica

USDA symbol: NAJA5

Life cycle: perennial

Habit: forb

Native status: Non-native, reproduces and persists in the wild in Canada âš˜ Non-native, reproduces and persists in the wild in the lower 48 states  

Synonyms: Nanozostera americana (Hartog) P.S. Toml. & U. Posl. (NAAM3)  âš˜  Zostera americana Hartog (ZOAM)  âš˜  Zostera japonica Asch. & Graebn. (ZOJA2)  âš˜  Zostera nana Roth (ZONA)   

Dwarf Eelgrass: Why This Marine Plant Isn’t Right for Your Garden If you’ve stumbled across the name dwarf eelgrass while researching plants for your garden, you might be wondering if this sounds like a perfect addition to your landscape. Well, here’s where things get interesting – and perhaps a little ...

Dwarf Eelgrass: Why This Marine Plant Isn’t Right for Your Garden

If you’ve stumbled across the name dwarf eelgrass while researching plants for your garden, you might be wondering if this sounds like a perfect addition to your landscape. Well, here’s where things get interesting – and perhaps a little disappointing if you were hoping to add it to your flower beds!

What Exactly Is Dwarf Eelgrass?

Dwarf eelgrass (Nanozostera japonica) is a perennial marine plant that’s quite different from what most gardeners typically work with. This little aquatic forb doesn’t have woody stems and lives its entire life underwater in saltwater environments. You might also see it referred to by its scientific synonyms, including Zostera japonica or Zostera nana, but they’re all the same plant.

Where You’ll Find It Growing

This marine plant has made its home along the Pacific Coast, specifically in British Columbia, Oregon, and Washington. Originally from Asia, dwarf eelgrass has established itself in North American waters where it reproduces on its own in the wild.

Why It’s Not Your Typical Garden Plant

Here’s the thing about dwarf eelgrass – it’s what we call an obligate wetland species, which means it almost always needs to be in wetland conditions. But not just any wetland will do! This plant specifically requires:

  • Saltwater marine environments
  • Shallow intertidal zones
  • Underwater growing conditions
  • Coastal marine ecosystems

So unless you have a saltwater aquarium setup or are involved in marine restoration projects, this isn’t going to work in your backyard garden, rain garden, or even your pond.

What Role Does It Play in Nature?

While dwarf eelgrass won’t beautify your flower borders, it does serve important ecological functions in marine environments. As a seagrass, it helps stabilize sediments and provides habitat structure in coastal waters, though specific details about its wildlife benefits aren’t well documented.

Better Alternatives for Your Garden

If you’re attracted to the idea of grass-like plants for wet areas in your garden, consider these native alternatives instead:

  • Native sedges (Carex species) for wet garden areas
  • Native rushes (Juncus species) for pond margins
  • Wild rice (Zizania species) for larger water features
  • Native wetland grasses suited to your specific region

The Bottom Line

While dwarf eelgrass has its place in marine ecosystems, it’s simply not suitable for traditional gardening applications. This underwater marine plant needs very specific saltwater conditions that most gardeners can’t provide. Instead of trying to grow something that won’t thrive in your space, focus on native wetland plants that will actually flourish in your garden conditions and provide benefits to local wildlife.

If you’re passionate about supporting marine plant conservation, consider getting involved with local coastal restoration projects where dwarf eelgrass and other marine species can be properly managed and appreciated in their natural habitat.

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 work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags 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. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Western Mountains, Valleys, and Coast

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Dwarf Eelgrass

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Alismatidae

Order

Najadales

Family

Zosteraceae Dumort. - Eel-grass family

Genus

Nanozostera P. Toml. & U. Posl. - eelgrass

Species

Nanozostera japonica (Asch. & Graebn.) P. Toml. & U. Posl. - dwarf eelgrass

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