Dallisgrass: What Every Gardener Should Know About This Widespread Perennial Grass
If you’ve ever wondered about that persistent, clumping grass growing in pastures, roadsides, or even creeping into your lawn, you might be looking at dallisgrass (Paspalum dilatatum). This perennial grass has quite the story to tell, and whether you’re dealing with it as a welcome guest or an unwanted visitor largely depends on your gardening goals and location.
Getting to Know Dallisgrass
Dallisgrass, also spelled Dallis grass, is a perennial bunch grass that grows in distinctive clumps. This graminoid (that’s botanist-speak for grass-like plant) reaches about 3 feet tall at maturity and has a decumbent growth habit, meaning it tends to spread along the ground before growing upward. With its moderate growth rate and green foliage, it might not win any beauty contests, but it’s certainly made itself at home across much of the United States.
Where You’ll Find Dallisgrass
Originally hailing from South America, dallisgrass has become a non-native resident throughout much of the United States. You can find it established in Alabama, Arizona, Arkansas, California, Colorado, District of Columbia, Florida, Georgia, Hawaii, Illinois, Kentucky, Louisiana, Maryland, Mississippi, Missouri, New Jersey, New Mexico, North Carolina, Oklahoma, Oregon, South Carolina, Tennessee, Texas, Virginia, West Virginia, as well as in Guam, Puerto Rico, and other U.S. territories.
The grass has proven quite adaptable, reproducing spontaneously in the wild without human assistance and persisting across diverse climates from the humid Southeast to the arid Southwest.
Garden and Landscape Role
Let’s be honest – dallisgrass isn’t typically anyone’s first choice for ornamental landscaping. Its coarse texture and somewhat unremarkable appearance make it more of a utilitarian plant than a showstopper. However, it does serve specific purposes:
- Erosion control on slopes and disturbed areas
- Quick ground cover establishment
- Forage grass in agricultural settings
- Wildlife habitat in naturalized areas
Growing Conditions and Care
Dallisgrass thrives in USDA hardiness zones 8-11, requiring at least 165 frost-free days annually. Here’s what this grass prefers:
- Soil: Adapts to medium and fine-textured soils; struggles with coarse, sandy soils
- pH: Prefers slightly acidic conditions (4.9-6.5)
- Moisture: High water requirements (35-60 inches precipitation annually)
- Fertility: Needs nutrient-rich soils
- Light: Intermediate shade tolerance but grows best in full sun
The grass shows high tolerance for fire and anaerobic conditions, making it persistent in areas with seasonal flooding or periodic burning.
Wetland Adaptability
One of dallisgrass’s notable characteristics is its flexibility regarding moisture conditions. Across most regions, it carries a Facultative wetland status, meaning it can thrive in both wetland and upland conditions. In Hawaii, it leans more toward upland areas but can still tolerate some wetness.
Wildlife and Ecological Benefits
While not a native species, dallisgrass does provide some ecological value. According to wildlife management sources, it contributes 5-10% of the diet for both small mammals and terrestrial birds, though these animals don’t typically use it for cover. The seeds are available from spring through summer, providing a seasonal food source.
Propagation and Spread
Dallisgrass reproduces primarily by seed, with approximately 281,200 seeds per pound. Seeds are commercially available and germinate with medium vigor. The plant blooms in mid-spring with inconspicuous yellow flowers, followed by brown seeds that persist briefly before dispersing at a moderate rate.
Should You Plant Dallisgrass?
Here’s where things get interesting. While dallisgrass isn’t necessarily harmful, its non-native status means it doesn’t provide the same ecological benefits as native alternatives. If you’re looking for a grass that serves similar functions, consider these native options instead:
- Native bunch grasses specific to your region
- Local sedges for wetland areas
- Indigenous prairie grasses for naturalized landscapes
If you already have dallisgrass established and it’s serving a purpose without causing problems, there’s no urgent need to remove it. However, for new plantings, native alternatives will better support local wildlife and ecosystem health.
The Bottom Line
Dallisgrass is one of those plants that’s neither hero nor villain – it’s simply a persistent, adaptable grass that’s found its niche across America. While it won’t transform your garden into a showpiece, it can serve utilitarian purposes in the right context. Just remember that choosing native plants when possible helps support the complex web of local wildlife that depends on indigenous flora.
Whether you’re managing existing dallisgrass or considering alternatives, understanding this common grass helps you make informed decisions for your specific landscape needs and conservation goals.
