Big Cordgrass: The Towering Native That Loves Getting Its Feet Wet
If you’ve ever wondered what that tall, graceful grass swaying in coastal marshes might be, there’s a good chance you’ve spotted big cordgrass (Spartina cynosuroides). This impressive native perennial is like the gentle giant of the grass world – reaching up to 8 feet tall and absolutely thriving in conditions that would leave other plants gasping for air.
Meet the Big Cordgrass Family
Big cordgrass goes by its scientific name Spartina cynosuroides, and while it doesn’t have many other common names, it’s sometimes listed under the synonyms Sporobolus cynosuroides or Spartina cynosuroides var. polystachya in older references. This rhizomatous perennial grass is a true American native, calling the lower 48 states home with a particular fondness for our eastern coastlines.
Where You’ll Find This Wetland Warrior
Big cordgrass has quite the extensive native range, stretching across 17 states from Massachusetts down to Texas. You’ll find it naturally growing in Alabama, Connecticut, Delaware, Florida, Georgia, Louisiana, Maryland, Massachusetts, Mississippi, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, Texas, and Virginia. This grass is classified as Obligate Wetland across all regions, meaning it almost always occurs in wetlands – and that’s your first big clue about its growing preferences!
What Makes Big Cordgrass Special
Standing tall at up to 8 feet, big cordgrass brings some serious vertical drama to wetland landscapes. Here’s what you can expect:
- Height and spread: Grows 8 feet tall with a moderate growth rate
- Appearance: Coarse-textured green foliage with yellow flowers (though they’re not particularly showy)
- Growth pattern: Spreads by rhizomes, forming colonies over time
- Seasonal interest: Dense summer foliage that becomes more open in winter
- Longevity: Long-lived perennial that’s active in spring and summer
Is Big Cordgrass Right for Your Garden?
Here’s the thing about big cordgrass – it’s absolutely fantastic, but only if you have the right conditions. This isn’t a plant for your typical flower border or dry garden bed. Instead, consider big cordgrass if you have:
- Wetland areas or rain gardens that need stabilization
- Coastal properties where salt tolerance is crucial
- Naturalistic landscapes mimicking native wetland ecosystems
- Erosion-prone areas near water features
- Large spaces where its spreading habit won’t be problematic
Growing Conditions: Water, Water Everywhere
Big cordgrass is refreshingly straightforward about its needs – it wants to be wet! Here’s what this moisture-loving grass requires:
- Moisture: High water needs; thrives in saturated soils
- Soil type: Adaptable to coarse, medium, and fine-textured soils
- pH range: 5.8 to 7.5 (slightly acidic to neutral)
- Salt tolerance: High – perfect for coastal gardens
- Sun requirements: Full sun (shade intolerant)
- Temperature: Hardy to -3°F, needs at least 210 frost-free days
- USDA zones: Approximately 4-10
Planting and Care Tips
The good news about big cordgrass is that once it’s established in the right spot, it’s relatively low-maintenance:
- Planting: Best propagated by bare root or sprigs rather than seed
- Spacing: Plant 2,700-11,000 plants per acre depending on your goals
- Establishment: Be patient – seedling vigor is low, so give it time to establish
- Fertilization: Medium fertility requirements
- Maintenance: Minimal once established; slow regrowth after cutting
- Spread control: Monitor rhizomatous spread in smaller gardens
Wildlife and Ecological Benefits
While big cordgrass may not be a showy pollinator magnet, it plays important ecological roles. As a wind-pollinated grass, it provides habitat structure and nesting sites for wetland birds and other wildlife. Its extensive root system (minimum 20 inches deep) helps prevent erosion and filter water runoff.
Potential Challenges
Let’s be honest about big cordgrass’s limitations:
- Space requirements: This isn’t a plant for small gardens – it needs room to spread
- Specific site needs: Without consistent moisture, it simply won’t thrive
- Limited drought tolerance: Don’t expect it to survive dry spells
- Slow establishment: Requires patience in the first year or two
The Bottom Line
Big cordgrass is a fantastic choice for the right situation – but that situation is fairly specific. If you’re working on wetland restoration, managing a coastal property, or creating rain gardens, this native grass could be exactly what you need. Its impressive height, salt tolerance, and erosion control capabilities make it invaluable in wet, sunny locations.
However, if you’re looking for a versatile grass for typical garden borders or don’t have consistently wet conditions, you’ll want to explore other native options better suited to your site. Remember, successful gardening is all about matching the right plant to the right place – and for big cordgrass, that place is definitely on the wet side!
