North America Native Plant

American Dunegrass

Botanical name: Leymus mollis mollis

USDA symbol: LEMOM2

Life cycle: perennial

Habit: grass

Native status: Native to Alaska âš˜ Native to Canada âš˜ Native to Greenland âš˜ Native to the lower 48 states âš˜ Native to St. Pierre and Miquelon  

Synonyms: Elymus arenarius L. ssp. mollis (Trin.) Hultén (ELARM)  âš˜  Elymus arenarius L. var. scabrinervis (Bowden) B. Boivin (ELARS2)  âš˜  Elymus arenarius L. var. villosus E. Mey. (ELARV4)  âš˜  Elymus capitatus Scribn. (ELCA12)  âš˜  Elymus mollis Trin. (ELMO9)  âš˜  Leymus arenarius (L.) Hochst. ssp. mollis (Trin.) Tzvelev (LEARM)   

American Dunegrass: The Coastal Champion Your Garden Needs If you’re looking for a tough, no-nonsense grass that can handle whatever Mother Nature throws at it, meet American dunegrass (Leymus mollis mollis). This hardy perennial grass is like the reliable friend who shows up in a storm – dependable, resilient, and ...

American Dunegrass: The Coastal Champion Your Garden Needs

If you’re looking for a tough, no-nonsense grass that can handle whatever Mother Nature throws at it, meet American dunegrass (Leymus mollis mollis). This hardy perennial grass is like the reliable friend who shows up in a storm – dependable, resilient, and surprisingly useful to have around.

What Makes American Dunegrass Special?

American dunegrass is a true North American native with an impressive resume. This rhizomatous grass calls home to an enormous range spanning from Alaska down to California, across Canada’s provinces, and even reaching into the Great Lakes region and northeastern United States. You’ll find it thriving in Alberta, British Columbia, Alaska, Manitoba, New Brunswick, California, Nova Scotia, Ontario, Prince Edward Island, Quebec, Saskatchewan, Northwest Territories, Nunavut, Illinois, Maine, Massachusetts, Michigan, New Hampshire, Oregon, Pennsylvania, Washington, Wisconsin, Labrador, and Newfoundland.

Also known by several scientific synonyms including Elymus mollis and Elymus arenarius subspecies mollis, this grass has been helping stabilize coastlines and challenging landscapes for centuries.

Why Your Garden Will Love American Dunegrass

American dunegrass isn’t your typical lawn grass – it’s so much better for specific challenging situations. Here’s why gardeners are increasingly turning to this coastal champion:

  • Erosion control superstar: Those spreading rhizomes create an underground network that holds soil together beautifully
  • Salt-tolerant: Perfect for coastal properties where salt spray kills other plants
  • Drought champion: Once established, it laughs at dry spells
  • Low maintenance: Set it and (mostly) forget it
  • Fast establishment: Rapid growth rate means quick results

The Nitty-Gritty: Size and Appearance

American dunegrass grows into substantial clumps reaching up to 4 feet tall with a coarse texture and dense summer foliage that becomes more open in winter. The foliage is an attractive green, and while it produces small yellow flowers in late spring, they’re not particularly showy – this grass earns its keep through function rather than flashy blooms. The growth form is distinctly rhizomatous, spreading underground to form colonies.

Perfect Garden Situations

This isn’t the grass for a manicured suburban lawn, but it’s absolutely perfect for:

  • Coastal landscapes and dune restoration
  • Erosion control on slopes and banks
  • Naturalized prairie or meadow areas
  • Xeriscaping and water-wise gardens
  • Challenging sites where other grasses fail
  • Wildlife habitat gardens (provides cover and nesting material)

Growing Conditions: Give It What It Wants

American dunegrass is surprisingly particular about some things while being incredibly tolerant of others:

  • Soil: Loves coarse, sandy soils but struggles in fine-textured clay
  • pH: Adaptable to slightly acidic to alkaline conditions (pH 6.0-8.0)
  • Moisture: Moderate water needs, but excellent drought tolerance once established
  • Salt tolerance: Exceptional – perfect for coastal conditions
  • Sun exposure: Full sun only – this grass doesn’t do shade
  • Temperature: Extremely cold hardy, tolerating temperatures down to 7°F

Planting and Care Tips

Getting American dunegrass established is straightforward if you follow these guidelines:

Planting: This grass is typically propagated by sprigs rather than seed, as seed production is minimal. Plant sprigs in spring or fall when temperatures are moderate. Space plantings 3,000 to 11,000 plants per acre depending on your coverage goals and timeline.

Establishment: While seedling vigor is considered low, once this grass takes hold, its rapid growth rate means you’ll see results relatively quickly. The underground rhizome system spreads at a moderate rate, gradually filling in gaps.

Maintenance: This is where American dunegrass really shines – it needs very little once established. No fertilizer requirements (it actually prefers low fertility), minimal watering after the first season, and no pest problems to speak of.

Seasonal care: Active growth occurs in spring and fall. The grass doesn’t retain leaves through winter but regrows vigorously each spring. After harvest or cutting, regrowth is slow, so avoid frequent mowing.

A Few Considerations

While American dunegrass is fantastic for the right situation, it’s not perfect for every garden:

  • It can’t handle foot traffic well, so it’s not suitable for play areas
  • The coarse texture won’t appeal to those wanting a refined lawn
  • It needs full sun and won’t tolerate any shade
  • Clay soils are a no-go – this grass needs good drainage

The Bottom Line

American dunegrass is a specialist that excels in challenging conditions where other grasses give up. If you have a coastal property, erosion issues, sandy soil, or just want a truly low-maintenance native grass for naturalized areas, this could be your perfect match. It’s commercially available and ready to prove that sometimes the toughest plants make the most reliable garden companions.

Give American dunegrass the right conditions – sandy soil, full sun, and room to spread – and it will reward you with years of dependable performance and the satisfaction of growing a true North American native that’s perfectly adapted to its environment.

How

American Dunegrass

Grows

Growing season

Spring and Fall

Lifespan

Long

Growth form & shape

Rhizomatous and Erect

Growth rate

Rapid

Height at 20 years
Maximum height

4.0

Foliage color

Green

Summer foliage density

Dense

Winter foliage density

Moderate

Foliage retention

No

Flowering

No

Flower color

Yellow

Fruit/seeds

No

Fruit/seed color

Brown

Allelopath

No

Nitrogen fixing

None

Toxic

None

C:N Ratio

High

Fire Resistant

No

Foliage Texture

Coarse

Low-growing Grass

No

Resproutability

No

Coppice Ability

No

Bloat

None

American Dunegrass

Growing Conditions

Adapted to Coarse Soil

Yes

Adapted to Medium Soil

No

Adapted to Fine Soil

No

Anaerobic tolerance

Low

CaCO₃ tolerance

High

Cold Stratification

No

Drought tolerance

High

Nutrient requirement

Low

Fire tolerance

High

Frost-free days minimum

150

Hedge tolerance

None

Moisture requirement

Medium

pH range

6.0 to 8.0

Plants per acre

3000 to 11000

Precipitation range (in)

30 to 60

Min root depth (in)

16

Salt tolerance

High

Shade tolerance

Intolerant

Min temperature (F)

7

Cultivating

American Dunegrass

Flowering season

Late Spring

Commercial availability

Routinely Available

Fruit/seed abundance

None

Fruit/seed season

Summer to Fall

Fruit/seed persistence

No

Propagated by bare root

No

Propagated by bulb

No

Propagated by container

No

Propagated by corm

No

Propagated by cuttings

No

Propagated by seed

No

Propagated by sod

No

Propagated by sprigs

Yes

Propagated by tubers

No

Seed per pound
Seed spread rate

None

Seedling vigor

Low

Small grain

No

Vegetative spread rate

Moderate

American Dunegrass

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Commelinidae

Order

Cyperales

Family

Poaceae Barnhart - Grass family

Genus

Leymus Hochst. - wildrye

Species

Leymus mollis (Trin.) Pilg. - American dunegrass

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