The STINKWORT (Dittrichia graveolens) can be our best teacher of grassland ecology or the worst weed ever, depending on what side of the California grassland fence you are on. --Are you maintaining exotic grasses in California for hay and grazing or are you restoring the original California native bunchgrasses and wildflower meadows?
Copyright text and photos © 2013, 2017, 2018 by Craig Dremann, The Reveg Edge, Box 361, Redwood City, CA 94064 (650) 325-7333
The Stinkwort was first noticed in California in Santa Clara County less than 30 years ago. The infestations on the San Francisco Peninsula are mainly spreading along the roadsides, and in 2017, this new weed has not been yet regularly eradicated each summer and autumn by any road management agencies, like those of Towns, Cities, County road crews or Caltrans highway maintenance crews..
Now that this new weed has spread to infest more than half of California's counties, government agencies are starting to pay attention, especially since this noxious weed is showing up in the Napa County vineyards and there are concerns that the plant might give an off-flavor to the wines.
Also there are concerns about the plant going
into the rangelands of the State, and injuring stock.
BLM on their web site has issued the following notice:
Warning! Touching stinkwort can cause dermatitis, itchy skin, or blistering. Grazers that eat this plant can produce tainted milk or meat. When the seeds are ingested by grazing animals they can cause inflammation of the small intestine, and can lead to pulpy kidney disease or sudden death.
Stinkwort is a California native tarweed-mimic, in that it has sticky stems and leaves and grows and flowers in the summer, after the annual weed grasses have died for the year. The original tarweeds could be called "exotic grazing-animal antibodies" in that they interfere with exotic animal grazing in California, and did not allow the animals to graze the land to barren dust and desert.
After 1865, when the perennial native grasslands were largely grazed to dust during the two year drought (William H. Brewer's accounts), then the non-palatable native plants like the tarweeds flourished in California between the 1870s to the 1920s.
The density of the tarweed in the 1920s in California grasslands can be seen in photos taken by Frederick Clements when he worked at Stanford at the Carnegie Institution. Since that time, ranchers have worked diligently to exterminate the native tarweeds and the other summer-blooming native wildflowers from rangelands. Tarweeds were probably largely wiped out after the invention of herbicides in the 1950s, so by the 1970s were absent in 99% of California grasslands.
Now, this exotic tarweed-mimic arrived, spreading quickly to fill the empty ecological niche left by the essentially extinct native tarweeds and other summer-blooming native plants. Stinkwort has now put a spotlight on the last 200 years of grassland mis-management in California.
When the original California native grassland
was exterminated, it included many tarweed species and other summer-blooming
members of the sunflower family like the Golden Aster (Heterotheca),
the Gumplants, the beautiful Lessengia and many others. Also
other summer-blooming native plants like the Buckwheats, Wild
Licorice, Spanish Clover, plus the Milkweed plants that are
needed by the Monarch butterflies to survive.
The Europeans and Americans were hoping that the palatable exotic grasses that were useful for grazing, plus the exotic filaree and exotic clovers and vetch species, would be the only plants to replace the now spatially-extinct native bunchgrasses and wildflowers.
However, an ecological rule is--When you exterminate an entire native grassland ecosystem and converting it to an exotic-plant biome, it is impossible to have fields of only the desirable wild oats and not expect the weedy exotics like Medusa head grass, Stinkwort and Yellow star thistle to follow. You cannot have the desirable filaree without the potential of having Stinkwort, Cheatgrass, or Italian thistles for example.
So, the battle begins for the empty tarweed ecological niche in California. If you are growing grapes for wineries, or grazing lands now covered with exotic grasses, or trying to maintain weed-free roadsides, expect to budget tens to hundreds of millions of dollars to keep Stinkwort from filling in that now-empty tarweed ecological niche.
Stinkwort's almost magnetic attraction to the open tarweed niche, plus the seed pappus allowing it to blow in the wind, will help this plant to eventually become perhaps one of the most hated weeds in California or maybe the worst weed in the Western United States.
However, if you are doing Ecological Restoration of the native bunchgrasses and wildflower fields, then this new weed can become your teacher, to grade your projects. Stinkwort can be used to indicate, wherever it grows, that you still have some more work to do on that spot of land, to fill in all of the proper native grassland ecological niches and puzzle pieces.
Who is financially responsible to pay for the eradications--SF Peninsula example.
The Stinkwort was put on the State Noxious weed list, which means that it was automatically declared under law, to be a "public nuisance". So then, the Food and Agriculture codes giving the County Agriculture Commissioners the power to issue abatement orders, should have followed immediately thereafter, in order to stop the infestations of this new weed from spread from property to property.
The Stinkworts have been making their way up the San Francisco peninsula, following Caltrans roadside up US 101 and I-280, then started moving across the Peninsula along East-West highways like 92 from US 101 to the Coast Highway One. Then, these roadside infestations of scattered plants along the freeways, start spreading downwind in a cone-shaped pattern to start large infestations. It looks like small fires getting started, and then in turn, throwing embers downwind, to start larger fires.
The Towns of Los Altos Hills, Palo Alto and Stanford have the largest infestations so far. The Stinkworts growing along nearly every roadside in the Town of Los Altos Hills, and several multi-acre infestations on the Stanford Hills between I-280 and the Dish, thick along the trails off Foothills Expressway and also on either side of the SLAC building, getting into the Jasper Ridge preserve, and also getting started in the middle of the 100+ acre Woodside Horse Park along Sand Hill Road. The infestation in the old Palo Alto baylands dump, is providing a home for the weed in that area.
On the SF Peninsula, all of the remaining native grasslands are threatened, especially the serpentine grasslands with many rare and Listed Endangered plants and insects that live between Palo Alto and the Crystal Springs reservoirs, plus the grassland habitat with their Endangered species on San Bruno Mountain.
In the Stinkwort's cross-hairs are Jasper Ridge at Stanford, Edgewood Preserve, SFPUC serpentine grasslands along the Crystal Springs lakes, and the grasslands of San Bruno Mountain.
Three of the Mid-Pen. Open Space preserves, Monte Bello, Rancho San Antonio, and Fremont Older are already infested, according to the Calflora database. And, in the fall of 2017, the stinkwort plants are seen growing along Skyline Blvd. (Highway 35) within a few feet of three other Mid-Pen. preserves, Skyline Ridge, Russian Ridge and Windy Hill.
Stinkwort plants growing along the coast at Pilar Point were photographed October 31, 2017 and that location was recorded in the Calflora data base, as was another occurrence near Montara, so that means all of the grassland habitats along the Highway One are also vulnerable.
So who should pay for all of these infestations on the SF Peninsula? There are at least six agencies at fault for not abating a public nuisance, and have cause damages that will cost millions of dollar per year to eradicate that nuisance that has spread to neighbor's properties.
County Agriculture Commissioners so far, has not issued any abatement orders. The two County governments, Santa Clara and San Mateo are the agencies that are legally responsible for sending out the abatement notices to start the Stinkwort cleanup.Since the Agriculture Commissioners have not yet issued abatement orders to stop the Stinkwort from spreading each year, should they be financially responsible for the costs of eradication on both public and private properties?
Negligent Roadside Maintenance managers and Negligent Land managers pay their share of the Stinkwort eradication and native plant restoration costs? Then, a list of land managers could be made, who have not adequately abated this new public nuisance on their lands, and have allowed the Stinkwort to spread and infest their neighbors. For example, Caltrans, County Road maintenance departments, City of Los Altos Hills road maintenance, Palo Alto's old baylands dump site and Mid-Pen. Open Space Trust infested preserves that have not been cleaned up yet, could be on that list?
ESTIMATED ANNUAL COSTS on the SF Peninsula. Estimated that to eradicate the existing Stinkwort, if the work started in 2017-2018, that each agency in the area would need to put together reasonable annual budgets to eradicate the Stinkwort on the Peninsula north of Cupertino, and once eradicated, keep it from being reintroduced.
Perhaps best to plan to use half of those funds to hire professionals like the company - Adopt-A-Highway.com to eradicate the plants along the roadsides, on the public lands and to eradicate the plants on the private lands. And then use the other half of the funds, to grow out the necessary bulk local native seeds, and sow those native seeds to take the place of the Stinkwort to keep that weed out permanently?
The agencies who should be responsible for the Stinkwort costs, total $10.8 million for the extent of the infestation in January, 2018. Costs will increase greatly every year that eradication is deferred--
Caltrans - $6 million
Santa Clara County - $1.2 million
Stanford - $1 million
San Mateo County - $500K
Los Altos Hills - $300K
Mid-Peninsula Open Space - $200K
National Parks Service - $100K
Palo Alto - $100K
Portola Valley - $100K
POST - $100K
SFPUC Crystal Springs - $100K
State Parks - $100K
WHERE COULD the Stinkwort money COME FROM??--Many
of these agencies and cities, already have in their annual budgets,
a category called "Unallocated Funds"
To cover the annual costs of eradication of the Stinkwort on the SF Peninsula, these unallocated funds could be that source of money, and at this point in time in the infestation, would require less than 1% of those funds. Here are current examples of the scale of these funds, that could be made available--
Caltrans -- $20 Million
Los Altos Hills -- $5.4 million
Mid-Pen. Open Space - $16.8 million
Palo Alto City - $56 million
Portola Valley - $4.9 million
San Mateo County - $154 million
Santa Clara County - $365 million
SFPUC Crystal Springs watershed - $9.3 million
Stanford University - $20 million.
ADOPT-A-HIGHWAY by the three big companies in the area? There is a company, Adoptahighway.com, that you can hire to go our and manage weeds along highways for you, so you do not have to risk your life to do that work.
Since most of the Stinkwort on the SF Peninsula is still growing along highways, the three big companies in the area could pay to adopt whole stretches of highways to eradicate the Stinkwort. For example AMAZON could adopt Highway 92, APPLE could adopt I-280 and FACEBOOK could adopt US 101 from Gilroy to San Francisco.
FINAL Stinkwort FIX. By commercially reproducing the bulk seeds of those local grassland native seed, they could be sown to fill in the empty ecological niche, and keep out the Stinkwort, the Yellow star thistle and any other weeds that are currently taking advantage of that empty niche.
This bulk native seed sowing needs to be done in November and December, after the weeds are sprayed in August to October, so the native seedlings can suppress the stinkwort seedlings the next summer.
Invent the best native sowing methods? A significant portion of the native seeding budget needs to be set aside, in order to hire professionals in Ecological Restoration to invent the best sowing methods for each native seed species, especially to produce successful planting along Caltrans roadsides, and within the public grassland preserves like Edgewood Preserve, or the SFPUC watershed.
STOP-GAP hand removal of small infestations - I did an experiment on December 9, 2017 on a 500-plant infestation. Before it rains, you need tree branch lobbers to be able to cut the thick tough stems at their base. However, after the rains have moistened the ground, and the plant turn from green to tan, they can easily be hand pulled. On this date, most of the seed were still attached to the plants.
We hand-pulled the 500 plants, carefully put them in piles, then took a 33 gallon plastic garbage can and lined it with a tough 33 gallon trash bag. By folding the plants over the can, any loose seeds would fall into the can as we stuffed the plants to fit into the can. About 100 plants can fit into a 33 gallon trash bag, and about 200 plants per hour can be hand pulled and bagged per person.
The next issue comes up--what to do with all of these hundred of thousands of ripe Stinkwort seeds--green waste bin or black trash bin. If it is put into the green waste bin, then it must be take out of the plastic bags, and when dumped into the truck, could fly out of those open truck tops, and scatter itself along the highways like Johnny Apple seeds sowing.
That is the only method I can see, how the entire length of Hwy 92 got totally infested, that is the route that the dump truck take to go from the transfer station in San Carlos, to the landfill site near Half Moon Bay at Ox Mountain. So maybe the best method is to keep it in the plastic bags, so it does not distribute seeds on the way to the landfill?
Hand-pulling with volunteers or prison labor, should never be considered by open-space,
park or roadside managers, because this weed is moving much to
quickly to get the job done using unpaid or slave labor. Instead
adequate budget need to be put together each year, and the proper
CEQA documents filed, so that your agency can get out every summer
and eradicate every plant on your property, with the most effective
herbicides while they are flowering and before they start producing
seeds. And keep doing that annual eradication process, until every
plant on the SF Peninsula is gone, and hopefully replaced with
a local native summer-blooming wildflower in its place.
BAGGING and KILLING the seeds.
Fortunately during dry weather in fall to winter, the Stinkwort plants still retain a lot of seeds on them, so during the dry spell on December 9, 2017, my crew carefully cut and bagged 500 plants, and we invented methods to hand-manage plants while they are still full of seeds, and before the rains.
-- CUTTING and PULLING PLANTS--For large plants, use heavy duty tree branch lobbers, and cut them at the base. For smaller plants, after the rains have softened the soil, those plants can be hand-pulled.
-- 33-GALLON GARBAGE CAN and BAGS--Get a 33 gallon plastic garbage can, and line it with double heavy duty plastic trash bags. Wearing gloves, the plants can be folded in half or thirds to fit into the garbage can, and if any seeds are shed in the process, do your plant-folding over the open garbage can to catch any the drop.
You double-bag the garbage bags, because the stem ends can sometime tear though a single bag.
--#64 RUBBER BANDS to SEAL BAGS--You can then crush the plants into the can, and tightly seal the end when the bags are full. It might be easiest to use large rubber bands to seal the ends of the garbage bags, using the #64 bands that you can buy at Staples or Office Depot, and wrap the band to seal the opening tightly. Then, place the bags in the sun for 2-3 days.
--MOISTURE in bag helps KILL SEEDS--The moisture that still remains in the plants, will force all of the seeds to shed in the bag within 12 hours, and within 2-3 days in the sun and with the moisture in the bag, the seeds will become sterile. So, once the moisture and sun has sterilized the seeds, then the cut Stinkwort plants can safely be taken out of the plastic bags and put into the green recycle bins.
By using rubber bands, you can easily open the bags once they have been sun-treated, to pour out the Stinkwort plants. Or use a sharp knife and cut the bags open lengthwise, and peel the bags away, so that you do not get any seeds airborne by shaking the plants out of the bags.
About 120 Stinkwort plants will fit into a 33-gallon garbage bag, and the plants in one bag weigh less than 10 pounds per bag, so are very easy to transport, although bulky. 500 plants in five 33-gallon bags will fit into a 1994 Saturn station wagon, for example.
--ADD WATER to garbage bag to give EXTRA MOISTURE--If you want to make sure to kill the seeds, add water to the plants in the garbage bag before you seal the bag, so the seeds get a double dose of moisture. That way, while you put the bags in the sun you cook the seeds and kill them better. Pour 3-4 cups of water into the bag before you seal it, and then after you seal it, shake the water around inside the bag, and put the bag in the sun for 3-4 days.
Stinkwort seed and seedling a week old,
graduation on tape measure are in 1/32nd of an inch.
--CHECK seeds, on moist cotton to make sure they are DEAD--You can double check that you have killed the seeds, by putting some seeds from the bottom of one of the cooked bags, and put the seeds on top of moist cotton for 10 days at room temperature, and check for any germination, which should be zero
OCTOBER-DECEMBER 2017 ROADSIDE SURVEYS by Craig Dremann.
Overview of survey area, above. 26 highway and local roadsides were surveyed on the San Francisco Peninsula October-December 2017 to provide a benchmark in time, of the location and extent of the Stinkwort infestations, with a focus on San Mateo County.
Total of 310 miles, and Stinkwort was seen along 82.75 miles or about 27%. Surveys were conducted 1/4 mile by 1/4 mile, and Lat/Long coordinates down to 0.00001 degree are available for each location, except for parts of Highway One and all of Highway 17. Total of 1,241 data points.
Free to use this data, without a copyright license, only must cite the source.
SURVEY Hwy One - South
of Princeton - HERE
SURVEY Hwy 9 - From Highway
35 to Saratoga - HERE
SURVEY Hwy 35 - South
of Hwy 84 - HERE
SURVEY Hwy 85 - From Saratoga
Av. north to US 101 - HERE
SURVEY Hwy 92 - Hwy 101 to I-280 - HERE
SURVEY Hwy 92 - I-280
to Hwy One - HERE
SURVEY US 101 - Candlestick Point to Hwy 92 - HERE
SURVEY US 101 - Hwy 92 to Woodside Road - HERE
SURVEY US 101 - Woodside
Road to Lawrence Expressway - HERE
SURVEY I-280 - Hwy 92 to Sneath - HERE
SURVEY I-280 - Hwy 92 to Edgewood exit - HERE
SURVEY I-280 - Edgewood exit to Page Mill Road - HERE
SURVEY I-280 - Page Mill Road to Foothill Expressway exit - HERE
SURVEY I-280 - Foothill Expressway to WInchester Blvd. - HERE
SURVEY ALPINE ROAD - HERE
SURVEY ARASTRADERO ROAD - HERE
SURVEY CANADA ROAD - HERE
SURVEY JUNIPERO SERRA/FOOTHILL EXPRESSWAY - HERE
SURVEY LOS TRANCOS ROAD - HERE
SURVEY PAGE MILL ROAD - HERE
SURVEY SAN BRUNO MTN.-Guadalupe Parkway - HERE
SURVEY SAND HILL ROAD - HERE
ROAD - HERE
SURVEY I-380 - HERE
SURVEY HIGHWAY 17 - HERE
SURVEY US 101 south of Hwy 87 to Hwy 152 - HERE
SURVEY Hwy 152 east of US 101 to Hwy 33 - HERE
SURVEY I-5 north from Hwy 33 - HERE
SURVEY Start I-5 go west to Lick Obser. Hwy
130 to Alum Rock/101 - HERE
SURVEY - DETAILS of the TOTAL MILES - HERE
P.S. -- Public nuisances and who is financially
liable?--New legal decision in the Santa Clara County Court case
about Public Nuisances. People v.
Atlantic Richfield Co., Santa Clara
Superior Court Case No. 1-00-CV-788657, the court ordered three
paint companies to pay $1.15 billion into a fund dedicated
to abatement of lead paint in pre-1978 homes.The judge found that
a plaintiff need not show that a defendant is the sole cause of
the injury, but rather that its conduct played more than an infinitesimal
or theoretical part in bringing about the injury, damage or loss.
This court case greatly expanded who is legally liability
to pay for abatement of a public nuisance, and for paying damages.
Updated January 21, 2018. Back to Craig Dremann's main Contents page.