Alien Invasion, Part 8:

Veldt Grass

Veldt grass (Ehrharta calycina) is a member of the grass family Poaceae. It is listed in the California Exotic Pest Plant Council’s List A-2: “Most Invasive Wildland Pest Plants; Regional.” This weed is found on coastal dunes and in sandy soils near the central coast of California. It is an annual-perennial grass, and is another invasive weed in the Elfin Forest that is native to South Africa. There are two other related species of invasives in California, Ehrharta longiflora to the south in the San Diego area, and Ehrharta erecta to the north, especially in the San Francisco bay area. All three come from South Africa.

Veldt grass (Ehrharta calycina)

The University of California introduced Ehrharta calycina to the central coast for erosion control in grazing lands. Until recently, the University actively imported the seeds. Cattle still use it for forage. Unfortunately, this grass has spread rapidly along disturbed areas such as roadsides and into native shrub communities. Veldt grass pushes aside and out-competes native plants, especially in disturbed soils, resulting in a rapid conversion of these areas into grassland ecosystems. Although introduced heavily into the southern portions of the county near the Nipomo dunes, veldt grass now virtually covers most of the vacant lots and roadsides near Los Osos- Baywood Park as well. The infestation was virtually invisible only a few decades ago. Now it is especially easy to see along South Bay Boulevard. In many areas, few individual native plants can be seen. Locally, veldt grass has converted coastal dune scrub and chaparral communities into grasslands. Veldt grass has had a devastating effect on native plants and the wildlife species that depend on them.

Veldt grass has an especially disastrous effect on mock heather (Ericameria ericoides). This plant is a favorite residence for the federally endangered El Moro Shoulderband dune snail. Thus veldt grass is expected to hurt dune snail populations both in and out of the Elfin Forest.

Veldt grass can be distinguished from other grasses in that it is a bunch grass that initially sprouts blue-green stalks in the winter and early spring when young. The joints in the stalks and the base of each leaf at that point have a red-purple ring. Some of the leaves acquire this red-purple color as the grass matures. The stalks reach heights of from 12 to 30 inches. In the late spring and early summer, the plant produces many small seeds on the main stalk and branches near the top six to ten inches. The seeds and branches all face the same direction. As the seeds mature, the seeds and stalks turn from reddish to a pale golden brown. Each seed begins as a tight bundle which then opens to form a two or three-pointed configuration. Once the seeds fall off the stalk, a two-pointed, v-shaped husk remains. In a mild year, veldt grass can be seen going to seed from late fall to late spring. It is a very prodigious seed producer, giving rise to a rapid expansion in infested areas. Seeds remain viable in the soil for at least three years.

Ehrharta calycina has spread throughout much of the Elfin Forest, infesting at least the southern two-thirds of the park. It is especially prevalent in the large disturbed plateau area east of Bush Lupine Point. This area was badly eroded and denuded of ground cover by motorized vehicles in the past. The veldt grass infestation is also severe along the southern park boundary near homes and along the eastern boundary at South Bay Boulevard. The hillside along South Bay Boulevard has been the site of a restoration project by the Land Conservancy. They removed the veldt grass and planted various native species that might compete with the invasive. Several years of continued maintenance are required.

Mechanical control of veldt grass is most effective by uprooting its shallow root system when the plants are young and have no seeds to be accidentally broadcast. The plants can be removed or composted or left to desiccate on the surface if there are no seeds. However, each year that seeds fall to the surface requires doing at least four years of maintenance and replanting with native plants to effectively eradicate the invasive.

The common household herbicides will kill veldt grass in yards, but far more effective industrial ones include Fusilade and Transline (not available to homeowners). Usually follow-up is required for at least one year after the initial spray.

No biological controls (insects, etc.) are available at this time. No one expects USDA to approve one in the near future. The closeness of veldt grass to important agricultural grasses and grains rules out biological controls. The risk of harm to agriculture is too great.

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