Photo: Steven BodzinCC BY 4.0via iNaturalistresized / cropped
Smooth Cordgrass Plant Care
Spartina alterniflora Loisel.
Updated · Sources · How we source care data
With its long, slender, bright green leaves and distinctive rhizomes, this plant originates from the salt marshes of North America's East Coast. Plant collectors are drawn to its ability to thrive in saline environments, making it a unique and resilient addition to any collection.
Every 3–7 days
Full sun to partial shade
50–90°F
40–70%
At a glance
How do you care for Smooth Cordgrass?
Water Smooth Cordgrass every 3–7 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 50–90°F (10–32°C) and 40–70% humidity. Fertilize it every 2 months during the growing season.
What Is the Smooth Cordgrass?
Smooth Cordgrass (Spartina alterniflora) belongs to the Poaceae family within the Spartina genus. Smooth Cordgrass is native to intertidal wetlands, especially estuarine salt marshes. Smooth Cordgrass is also known as Saltmarsh Grass, Saltmarsh Cordgrass, Switchgrass.
Smooth Cordgrass displays a tall, grassy clumps growth habit, reaching up to 4 ft tall with a spread of approximately 2 ft. Smooth Cordgrass produces feathery flower spikes in shades of green, brown, or purple.
Leaf size: approximately 12 inches.
How Often Should You Water a Smooth Cordgrass?
Spartina alterniflora requires watering every 3–7 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 3–7 days
Let soil partially dry between waterings
What Light Does the Smooth Cordgrass Need?
Smooth Cordgrass thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Smooth Cordgrass Prefer?
Spartina alterniflora grows best at temperatures of 50–90°F. Smooth Cordgrass prefers humidity levels of 40–70%.
Temperature
50–90°F
Humidity
40–70%
What Soil Mix Works Best for a Smooth Cordgrass?
Moist, fertile soil with good drainage. Good drainage is essential for Smooth Cordgrass to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Smooth Cordgrass?
Feed Smooth Cordgrass every 2 months during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.
Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.
Fertilizing
Every 2 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Smooth Cordgrass?
Divide clumps every 2-3 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Smooth Cordgrass?
Smooth Cordgrass can be propagated through division, seed. Similar propagation techniques also apply to giant cordgrass plant care, which shares the same genus.
Is the Smooth Cordgrass Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Smooth Cordgrass, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Smooth Cordgrass?
Smooth Cordgrass is susceptible to aphids, grasshoppers, caterpillars. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Smooth Cordgrass Need?
Smooth Cordgrass grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Smooth Cordgrass is native to intertidal wetlands, especially estuarine salt marshes. In cooler regions, grow Smooth Cordgrass as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Smooth Cordgrass is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Spartina genus — compare its care with other Spartina species on PlantoScan.
Spartina is part of the Poaceae plant family — browse all Poaceae genera and species.
Smooth Cordgrass thrives in bright light and direct sun — see other bright-light plants.
Related Plant Care Guides
Closely related plants with similar care requirements:
Sources
- Scientific name & taxonomy: Spartina alterniflora Loisel., family Poaceae (first published in Fl. Gall. : 719 (1807)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Smooth Cordgrass, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Photo: Steven Bodzin, CC BY 4.0, iNaturalist — original.
- Hardiness zone: USDA Zone 12a, calculated from the plant's minimum temperature.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
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