North America Non-native Plant

Seaside Barley

Botanical name: Hordeum marinum marinum

USDA symbol: HOMAM

Life cycle: annual

Habit: grass

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

Synonyms: Critesion marinum (Huds.) Á. Löve (CRMA20)   

Seaside Barley: A Hardy Coastal Grass for Challenging Gardens Meet seaside barley (Hordeum marinum marinum), a tough little annual grass that’s made itself at home along America’s coastlines. While it might not win any beauty contests, this unassuming plant has some interesting qualities that make it worth knowing about, especially ...

Seaside Barley: A Hardy Coastal Grass for Challenging Gardens

Meet seaside barley (Hordeum marinum marinum), a tough little annual grass that’s made itself at home along America’s coastlines. While it might not win any beauty contests, this unassuming plant has some interesting qualities that make it worth knowing about, especially if you’re dealing with challenging growing conditions.

What Exactly Is Seaside Barley?

Seaside barley is an annual graminoid – that’s just a fancy way of saying it’s a grass-like plant that completes its entire life cycle in one year. Originally from Europe and the Mediterranean, this hardy little survivor has established itself in parts of California, New Jersey, and Oregon. It’s also known by the scientific synonym Critesion marinum, in case you run across that name in your plant research.

Why Would You Want (Or Not Want) Seaside Barley?

Here’s the thing about seaside barley – it’s not exactly a showstopper, but it has its place. This grass thrives in conditions that would make other plants throw in the towel:

  • Excellent salt tolerance for coastal gardens
  • Drought resistant once established
  • Grows in sandy, poor soils
  • Low maintenance annual
  • Self-seeds readily

However, since it’s a non-native species, you might want to consider native alternatives that provide similar benefits while supporting local ecosystems.

Growing Conditions and Care

If you decide to grow seaside barley, you’re in luck – it’s pretty much a plant-it-and-forget-it situation. This grass prefers:

  • Sunlight: Full sun exposure
  • Soil: Sandy, well-draining soils (poor soils are actually preferred)
  • Water: Drought tolerant; minimal watering needed
  • Climate: Generally suited for USDA zones 8-10 in coastal areas

Planting and Maintenance Tips

Growing seaside barley is refreshingly simple:

  • Direct seed in fall or early spring
  • Barely cover seeds with soil – they need light to germinate
  • Water lightly until established, then let nature take over
  • No fertilizer needed (it actually prefers lean conditions)
  • Allow plants to self-seed if you want them to return next year

Garden Design Ideas

Seaside barley works well in:

  • Coastal restoration projects
  • Xerophytic (dry) landscape designs
  • Naturalized meadow areas
  • Areas with poor, sandy soil where other plants struggle

Consider Native Alternatives

While seaside barley isn’t considered invasive, supporting native plant communities is always a great choice. Consider these native grasses that offer similar benefits:

  • Native bunch grasses appropriate to your region
  • Local sedge species for similar texture
  • Regional salt-tolerant native grasses for coastal areas

Check with your local native plant society or extension office for the best native alternatives in your specific area.

The Bottom Line

Seaside barley is a tough, no-fuss annual grass that can handle challenging coastal conditions. While it may not provide the wildlife benefits of native plants, it can serve a purpose in difficult growing situations. Just remember to research native alternatives that might work equally well while providing better support for local ecosystems. Sometimes the most interesting plants are the ones that quietly do their job without making a fuss – and seaside barley definitely fits that bill.

Seaside Barley

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

Hordeum L. - barley

Species

Hordeum marinum Huds. - seaside barley

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