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Insidiously Invasive Elegance |
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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.
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.
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.
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.
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
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 831-385-5434 jkwasny/r5_lospadres@fs.fed.us
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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.
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.
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.
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.
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.