Pampasgrass and Jubatagrass Threaten California Coastal Habitats

What can be done to prevent further spread?

Nursery Industry. Soon after the introduction of pampasgrass into California, nurserymen preferentially selected the showier female plants. These plants were propagated through vegetative cuttings. Over a period of time, few male plants were sold as ornamentals. For this reason, pampasgrass rarely produced viable seed and was not previously considered a significant threat to escape cultivation.

Male pampasgrass

In recent years, however, some nurseries have propagated pampasgrass from seed. Since it is impossible to distinguish male and female plants before they flower, the result is an increase in the proportion of male plants in the population. Consequently, there has been an increase in the amount of viable seed produced and the species has escaped to become an invasive problem along the California coast, particularly in the southern regions. Furthermore, in some cases jubatagrass seed has accidentally been used to propagate nursery stocks. This has also contributed to the spread of the weed.

Most nurseries in California are well aware of the invasive qualities of jubatagrass and mixtures of male and female pampasgrass and take every effort to ensure that only female pampasgrass plants are produced and sold. It is critical that nurseries only propagate female pampasgrass through vegetative cuttings. Plants should never be grown from seed.

Preventing Establishment. Seeds do not appear to survive long in the soil. Seedling growth and establishment is most rapid on bare sandy soil and exposed road cuts, but typically requires a cool foggy climate and moist soil. Seedling survival is low in shaded areas or in competition with grasses or sedges. Thus, using mulches, such as straw, in disturbed sites can prevent jubatagrass and pampasgrass infestations. Ideally, overseeding disturbed sites with desirable vegetation can hinder the establishment of jubatagrass and pampasgrass seedlings.

Back to Pampasgrass & Jubatagrass main page

Forward to next page