Smooth Cordgrass Plant Care
Sporobolus alterniflorus (Loisel.) P.M.Peterson & Saarela
Updated · Sources · How we source care data
Sporobolus alterniflorus, or synonymously known as Spartina alterniflora, the smooth cordgrass, saltmarsh cordgrass, or salt-water cordgrass, is a perennial deciduous grass which is found in intertidal wetlands, especially estuarine salt marshes. It has been reclassified as Sporobolus alterniflorus after a taxonomic revision in 2014, but it is still common to see Spartina alterniflora and in 2019 an interdisciplinary team of experts coauthored a report published in the journal Ecology supporting Spartina as a genus.
Every 7–10 days
Full sun to partial shade
60–85°F
40–70%
At a glance
How do you care for Smooth Cordgrass?
Water Smooth Cordgrass every 7–10 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 60–85°F (16–29°C) and 40–70% humidity. Fertilize it every 8 months during the growing season.
What Is the Smooth Cordgrass?
Smooth Cordgrass (Sporobolus alterniflorus) belongs to the Poaceae family within the Sporobolus genus. Smooth Cordgrass is native to intertidal wetlands, especially estuarine salt marshes. Smooth Cordgrass is also known as Saltmarsh Cordgrass, Smooth Saltmarsh Grass, Cordgrass.
Smooth Cordgrass displays an upright, clumping grass growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Smooth Cordgrass produces small inconspicuous flowers on tall spikes.
Leaf size: approximately 12 inches.
How Often Should You Water a Smooth Cordgrass?
Sporobolus alterniflorus requires watering every 7–10 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 7–10 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?
Sporobolus alterniflorus grows best at temperatures of 60–85°F. Smooth Cordgrass prefers humidity levels of 40–70%.
Temperature
60–85°F
Humidity
40–70%
What Soil Mix Works Best for a Smooth Cordgrass?
Well-draining sandy loam with added organic matter. 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 8 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 8 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?
Repot every 1-2 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, seeds. Similar propagation techniques also apply to foxtail dropseed 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 grasshoppers, aphids, spider mites. 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 13a. It survives winters down to planting zone 13a. 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 13a
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 Sporobolus genus — compare its care with other Sporobolus species on PlantoScan.
Sporobolus 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.
More Sporobolus Species
Other Sporobolus species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Sporobolus alterniflorus (Loisel.) P.M.Peterson & Saarela, family Poaceae (first published in Taxon 63: 1236 (2014)) — 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.
- Hardiness zone: USDA Zone 13a, 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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