Insidiously Invasive Elegance
It's a common sight on Highway One in Big Sur all year, but on the Autumn Equinox the most noticeable invasive plant is pampas grass and the seeds pile up along the roadside like snow. High in the Santa Lucias - for example along the Cruikshank Trail in the Silver Peak Wilderness - pampas grass sprouts up from wind borne seeds. It's on Nacimiento Road as high as the summit (2600 ft.) and I found one down the east side of this road in the Nacimiento drainage! It's not unusual to find one growing in the deep shade of a redwood stream, on a deer trail in coastal scrub or on a grassy ridge at 2000 feet. Like cape ivy, sticky eupatorium or french broom, pampas grass is a problem plant because it spreads into wildlands even in the absence of man-made disturbance.
Weed control specialists refer to Cortaderia jubata as jubatagrass but I'll stick with pampas grass in this article because that is how it is locally known. Pampas grass is a misnomer. The plant we call pampas grass is really from the Andes - Ecuador, Peru and Chile - whereas the giant grass from the Pampas of Argentina (Cortaderia selloana) is a little better behaved and doesn't often spread here (though apparently that is happening more now in southern California). Selloana plumes are a silvery white and rise to about the same level as the leaves. You may see it as a landscape plant anywhere in central California. Selloana was a commercial crop grown for its showy plumes in the late 19th century both in the U.S. and Europe. It is also sold as C. quila, C. rudiscula and C. atacamensis. Jubata pampas grass plumes are reddish first then fade to a pale tan and they reach clearly above the leaf mass. Jubata makes a quicker flowering product for nursery sales so watch out if you think you're buying the safer selloana at the nursery. There has been confusion between the two over the years and thus, our current eyesore. It was allegedly brought to Big Sur's south coast near Lucia for landscaping by a prominent family in the 1960's.
Pampas grass consists of all female plants that reproduce by apomixis, a sort of self-cloning by seed. The delicate wind borne seeds mature quickly but have a poor germination rate. They make up for this by producing lots of seed and, in case you haven't noticed, they do fare very well in disturbed areas like roadcuts, eroded gullies and excavations. Yes, they do stabilize soil on roadcuts, but not as well as our native plants and they eliminate the diversity that makes healthy homes for big and small, two and four legged animals. The Caltrans maintenance folks from the north end of Big Sur spray pampas grass, french broom and other invaders regularly along Highway One making it hard for visitors to pull pampas fronds for souvenirs. For some reason, south of Anderson Canyon (a different maintenance crew) NO exotic plant control is done along the highway and this is where much of the highway is adjacent to Los Padres National Forest lands. No one at Caltrans has ever ever explained this inconsistency to my repeated inquiries. While pampas will never be eliminated from the steep coastal cliffs, if Caltrans removes it from Highway One, tourists can't pick it and contribute to seed spread elsewhere. If you run across a pampas plant in the wilderness, by all means feel free to try to root it out! Large plants become difficult but small first year plants are easy to pull even in the dry season. Young pampas starts may look like any other grass but the leaves are broader than most natives and it has a bristly sharp feel; indeed it's easy to cut yourself on the leaves. Pampas grass also responds well to glyphosate (Roundup), a fairly benign herbicide.
This article is the last in a series on invasive non-native plants that are spreading in Big Sur wildlands. The previous three Double Cone Quarterlies included articles on french broom, cape ivy and sticky eupatorium which, along with pampas grass, include the worst culprits. There are about 450 non-native plant species wild in Monterey County and most of them confine themselves to roadsides, agricultural lands and other developed disturbed areas. The ones that spread into wildlands without disturbance or after natural disturbance events like floods and fires often persist and alter the entire ecosystem. There are some others of less invasiveness or that are not yet widespread in Big Sur and I'll mention a few more here to watch out for.
What I think may become the french broom of the next millennium is also known as Victorian box or Pittosporum undulatum. It's spreading into coastal scrub at Julia Pfeiffer Burns State Park and along the highway in this vicinity and elsewhere in Big Sur. I have reports that it's common in coastal wetlands and shaded riparian areas in the Santa Barbara area. This fast growing Australian native can attain small tree size and is a landscaping favorite on the central coast with its shiny dark green leaves and small orange fruits with sticky seeds in the Fall, which I assume are transported by birds and other animals. The wavy leaf margins are conspicuous. This plant could be confused with California bay which has a somewhat wavy leaf margin but bay's pungent aroma is a give away and the Pittosporum leaves are a more yellow-green than bay which often grows from a large basal burl. I don't know how high it ranges in elevation and am interested in reports.
Fountain grass, Pennisetum setaceum, is an attractive perennial grass with a densely clumped growth form and erect stems that grow 2 to 3 feet high. The small flowers of fountain grass are grouped in pink or purple, bristly, upright inflorescences 6-15 inches long. Fruits are small achenes adorned with long showy bristles. It was introduced at Grimes Point as an ornamental in the 60's and now is seen along Highway One in this vicinity, where it seems to prefer the granite soils found there. In southern California from Santa Barbara south, it is a very common roadside weed. There is a coppery-colored supposedly sterile cultivar commonly seen in urban landscapes. Fountain grass is above the highway at Lafler Canyon (Coast Gallery) and likely occurs on the Hathaway parcel acquired by the USFS in 1988. Look on Boronda ridge if you come down that trail from Timber Top to Highway One and please let me know if you see it there.
Another Pennisetum is the ubiquitous kikuyu grass (P. clandestinum) so common along the highway in Big Sur, where it slowly penetrates asphalt turning it into soil. The mature plant forms a low mat with creeping underground stems and produces stout creeping stems that root at the nodes on the surface of the soil. Coastal scrub resists this grass well but after a fire or other disturbance, this grass resprouts faster than anything and spreads, slowly eating up habitat in the fogbelt. I haven't seen it in the wilderness proper but it's common in the grazed areas at Pacific Valley and the Hill Ranch at Point Sur. It's at the bottom of the Kirk Creek Trail and the campground. We've found it along the Big Sur River in Molera State Park having been washed downstream in floods from homesite landscaping upstream.
This covers the most worrisome plant invaders in our area. For more information on these plants and others check the website of the California Exotic Pest Plant Council. The Monterey chapter of the California Native Plant Society often sponsors field trips that include manual pampas grass removal (as well as less strenuous wildflower viewing) where it threatens native flora.
The USFS Los Padres National Forest-Monterey District is creating a Weed Management Area plan to coordinate the invasive weed efforts of public agencies and private landowners. Pampas grass is a target species at several District sites and is named in the District's 1999 Invasive Weed Control Environmental Assessment. To express your support for these projects and more information contact:
Jeff Kwasny, Resource Officer