Purple Love Grass (Eragrostis spectabilis) is a warm-season perennial grass native to a large portion of North America. Its vigorous self-seeding habit often leads many to question if it is an invasive species. Eragrostis spectabilis is not classified as invasive, a term reserved for non-native plants that cause ecological or economic harm. However, this native grass is known for being aggressive in garden settings and is considered a successful pioneer species that thrives in disturbed, open ground.
Identifying Purple Love Grass
This grass forms a low, softly mounding clump of fine-textured, blue-green foliage, typically reaching a height of 8 to 14 inches. The leaf blades are narrow and mostly basal, staying close to the ground. The most distinctive feature appears in late summer, when the plant produces large, airy panicles of flowers and seeds. These inflorescences are characterized by a delicate, hazy purplish-pink color, often creating a cloud-like effect that can nearly double the plant’s overall height.
Individual spikelets are flattened, purplish, and small, about 4 to 7 millimeters long. The plant gets the common name “tumble grass” from its unique dispersal method. At maturity, the entire seed-bearing panicle often breaks off from the stem and is tumbled across the ground by the wind, scattering its numerous seeds. Eragrostis spectabilis is a hardy plant that thrives in full sun and dry conditions, commonly found along roadsides, railroads, and in sandy or gravelly soils.
Native Status and Ecological Role
Purple Love Grass is indigenous to the United States, with a native range extending from Maine west to North Dakota, and south to Florida, Texas, and Arizona. It is a true native species that evolved within the North American ecosystem. The classification of a plant as “invasive” specifically requires it to be non-native and to cause significant harm, which does not apply to this species. While it can be weedy or aggressive in a garden, it is not ecologically invasive.
The grass plays a substantial role in maintaining the health of its native habitats, particularly in open woods, sand prairies, and disturbed sites. Its dense, fibrous root system anchors the soil and extends up to three-quarters of a meter deep, making it highly effective for erosion control and habitat remediation. This deep root structure helps to manage water runoff, making it a valuable component in water-wise landscapes and on unstable slopes.
As a warm-season bunchgrass, it provides habitat and resources for various wildlife, supporting the food web. The plant acts as a larval host for certain insects, such as the paradoxical grass moth, and is a food source for other insect herbivores like leafhoppers. The seeds are foraged by small animals and birds, which also use the dense foliage for nesting material and cover. Its ability to grow in poor, dry, and infertile soils allows it to stabilize land where other plants struggle, making it an early-successional species.
Managing Spread in Garden Settings
The aggressive reputation of Purple Love Grass in managed landscapes is due to its prolific self-seeding, especially in areas with open, sandy soil. The “tumble grass” behavior, where the seed head detaches and rolls, can spread seeds across a wide area if left unchecked. Gardeners seeking to contain its spread must focus on preventing the seeds from maturing and dispersing.
The most effective method for containment is deadheading the plant before the seeds are fully ripe in late summer or early fall. By cutting the airy flower stalks to the ground before they turn tan and detach, you can eliminate the source of new volunteers. If the plant is used as a groundcover, it can also be mowed a few times a year to prevent seed set, though this should only be done in areas with light foot traffic.
If unwanted seedlings appear, they are generally easy to remove in their early stages. Hand-pulling is a low-impact and effective removal technique, especially when the soil is slightly moist. Because Eragrostis spectabilis is a bunchgrass that spreads slowly by short rhizomes, individual clumps are not difficult to isolate or remove. Chemical control is rarely necessary but can be managed with selective herbicides if a large patch has established itself.