How to Grow Arrowgrass
Arrowgrass
Triglochin maritima
grassArrowgrass is a salt-tolerant perennial grass native to coastal and alkaline wetland regions across North America and Eurasia. It grows in dense clumps with thin, needle-like leaves and produces distinctive arrow-shaped seed heads. This hardy plant thrives in saline and brackish environments where most other plants cannot survive.
When should you plant Arrowgrass in your zone?
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Example Arrowgrass timeline · Pittsburgh, PA (Zone 6b)
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Plant Arrowgrass
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Arrowgrass
Around Jul 16≈ 90 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Arrowgrass dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Extremely cold-hardy; thrives in zones 2-9, particularly in northern and coastal regions
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Get my Arrowgrass timeline →Growth Stages
Germination
2-3 weeksTiny seedlings emerge with thin cotyledons and first grass leaves
Keep soil consistently moist but not waterlogged; provide light; germination occurs in 10-21 days
Vegetative Growth
6-8 weeksDense clumps of thin, needle-like basal leaves develop; plant gradually expands
Maintain moist soil; light fertilization with balanced fertilizer if needed; thin weak seedlings
Stem Elongation
3-4 weeksTall, thin flowering stems (culms) arise from the leaf clumps, reaching 12-30 inches tall
Ensure consistent moisture; support stems if in windy locations; stems are naturally upright
Flowering & Seed Development
4-6 weeksSmall greenish flowers appear in dense racemes; distinctive arrow-shaped seed capsules develop
Maintain adequate moisture; protect from excessive wind; allow seeds to mature fully on plant
Seed Maturity & Dispersal
2-3 weeksSeed heads turn brown and dry; arrow-shaped capsules split to release seeds or remain intact for wind dispersal
Collect seeds before full dispersal if saving seed; allow some to naturally spread; seeds can remain viable in soil
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Rarely serious; maintain plant vigor with adequate moisture and light; remove heavily infested plant material
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and
Hand-pick in wetland areas; encourage natural predators; use row covers if available
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Ensure good air circulation; remove infected leaves; improve drainage if possible; fungicide only if severe
Uses
Waterfowl and Livestock Forage
WildlifeArrowgrass provides nutritious forage for waterfowl and is browsed by salt-marsh grazing livestock, contributing to food security in coastal ecosystems. [source]
Wetland Restoration
HouseholdArrowgrass is used in coastal wetland restoration projects and constructed treatment wetlands to stabilize saline soils and improve water quality. [source]
Traditional Maritime Medicine
MedicinalIn some coastal Indigenous cultures, arrowgrass has been used in traditional remedies and poultices, though modern use is limited. [source]
Ornamental Wetland Plantings
CraftThe distinctive arrow-shaped seed heads and fine texture make arrowgrass an attractive choice for native plant gardens, rain gardens, and ornamental wetland installations. [source]
Soil Stabilization & Erosion Control
HouseholdDense root systems of arrowgrass anchor saline soils and prevent erosion in salt marshes and coastal dune edges. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Arrowgrass is not typically harvested for consumption or commercial use. For seed collection, harvest seed heads when they turn brown and begin to split, typically 4-6 weeks after flowering. Cut entire seed heads and dry them indoors in paper bags to collect mature seeds. Seeds can be stored in cool, dry conditions for several years.
Fun Facts
- 🌱 Arrowgrass is one of the few grasses that can thrive in salt concentrations comparable to seawater, making it invaluable for coastal habitat restoration.
- 🌱 The distinctive arrow-shaped seed pods (fruits) give the plant its common name and are a key identifying feature; they split into three parts to disperse individual seeds.
- 🌱 Arrowgrass is circumboreal and circumpolar, found naturally across Arctic and subarctic regions from North America to Siberia, demonstrating its extreme cold and salt tolerance.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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