Slender veldt grass (Ehrharta calycina), a perennial species from southern Africa, has established itself globally, including in Australia and California. This overview provides insights into recognizing and managing this adaptable plant.
Identifying Slender Veldt Grass
Slender veldt grass typically forms dense tussocks. It commonly grows 30 to 75 centimeters tall. The leaves are flat blades, ranging from green to reddish-purple. Leaf blades are 7 to 20 cm long and 2 to 7 mm wide, often wrinkled.
The ligule, an appendage at the leaf blade and sheath junction, is membranous with a ragged tip, sometimes hairy or reddish. Multiple stems may arise from a single tussock, featuring four to six hairless nodes, which can occasionally show a purple coloration.
The inflorescence (flower head) is a panicle, varying from contracted to openly arrayed, appearing linear or oblong. These structures are 10 to 15 cm long, initially light and darkening to purple or reddish as they mature. Flowering occurs in spring, with small, dark brown seeds developing in summer. Below ground, it develops a fibrous root system and can sometimes spread through short rhizomes.
Growth Habits and Preferred Environments
Slender veldt grass is a perennial species, consistently forming dense tufts or tussocks. It exhibits high growth rates, with rapid root development following rainfall. In areas with sufficient moisture, it can spread vegetatively and by seed, creating a continuous turf.
The plant tolerates drought and moderate frost. However, it does not thrive in waterlogged, oxygen-poor soils or high salinity levels. It readily colonizes disturbed areas like roadsides, and can infiltrate established vegetation, including heathlands, woodlands, and forests, especially after natural disturbances. It flourishes in various habitats, including sand dunes, coastal regions, and grasslands, typically preferring deep sandy soils. Reproduction is primarily through abundant seed production, dispersed by wind, water, animals, and human activities, contributing to persistent soil seed banks.
Ecological Impacts
Slender veldt grass significantly alters natural ecosystems. It directly displaces native plant species by outcompeting them for resources, often forming dense, single-species stands. This competitive dominance inhibits the germination and establishment of indigenous forbs and woody plants, reducing local plant and invertebrate diversity. The grass contributes to a rapid shift in vegetation composition, transforming diverse native communities into species-poor grasslands.
Beyond direct competition, it can modify soil’s chemical and physical properties. It may possess acid-secreting root hairs that increase nutrient availability, and can alter soil hydrology, potentially increasing water repellence. A concern is its impact on fire regimes. Its dry biomass accumulates during summer, providing ample fuel that can increase wildfire frequency and intensity. Fire, in turn, can further promote its spread by suppressing less fire-tolerant native species while enhancing its own establishment.
Management and Control Strategies
Effective management involves prevention. Encouraging dense native plant cover can deter its invasion. Preventing seed set for at least three years is a key long-term strategy, along with cleaning machinery and vehicles to avoid spreading seeds.
For smaller infestations, manual hand-pulling can be effective. Extract the entire plant, including the buried crown or base, to prevent resprouting. However, manual removal is labor-intensive and may inadvertently stimulate seed germination from the soil seed bank, necessitating repeated efforts. The optimal time for manual removal, including crown extraction, is generally between November and February.
Chemical control is also available. While non-selective herbicides like glyphosate can be effective, selective grass-specific herbicides minimize harm to broadleaf plants. Herbicides are best applied post-emergence to actively growing, non-stressed plants, ideally after most seedlings emerge or when plants are over 10 cm tall. Regular follow-up treatments are needed to manage new seedlings from the persistent seed bank, as ongoing management is necessary for sustained control.