Cal-IPC News
Protecting California’s Natural Areas
fr
om Wildland W
eeds
from
Weeds

Vol. 13, No. 1, Spring 2005

Quarterly newsletter of the California Invasive Plant Council

Ex
ceptional yyear
ear ffor
or
Exceptional
wildflo
wer
wildflow
erss… and
Sahar
an must
ar
d
Saharan
mustar
ard
Saharan mustard (Brassica tournefortii)
invading dunes near Borrego Springs
(shrubs at right of photo). This winter’s
rains have generated exceptional growth in
both native desert wildflowers and the
invasive mustard. See inside cover for more
information. (Photo Mike McCrary)

Inside:
Which weeds dominate southern California
riparian systems? …………………………………….. 4
Tools: Basal bark treatment, and broom
lopping results …………………………………………. 8
Japanese Knotweed Red Alert! ……………………. 10
Oakland discusses herbicides …………………….. 11

From the Director’s Desk

Taking a st
and
stand
California
Invasive Plant
Council
1442-A Walnut Street, #462
Berkeley, CA 94709
(510) 843-3902
fax (510) 217-3500
www.cal-ipc.org
A California 501(c)3 nonprofit organization

Protecting California’s natural areas
from wildland weeds through
research, restoration, and education.

The use of herbicides for wildland weed control can be a contentious issue. Many practitioners believe that herbicides are one of the most valuable tools in their restoration toolbox,
while others are determined to avoid their usage entirely.
What is Cal-IPC’s role? This spring, the Oakland watershed group Friends of Sausal Creek
contacted us as they worked to secure an exemption to the city’s strict IPM (Integrated Pest
Management) ordinance. After nearly a decade of restoration work in the watershed, the
group had decided that it needed to apply herbicides in a “cut stump” treatment to some
vigorous resprouters, such as eucalyptus, in particular situations. (See article page 11.)
In crafting our letter of support for their work, it became clear that what Cal-IPC supports is
the right of local communities to make informed decisions on their approach to restoration
work. This means sharing with them the current state of knowledge and practice from other
restoration efforts around the state.

Staff
Doug Johnson, Executive Director
dwjohnson@cal-ipc.org
Elizabeth Brusati, Project Manager
edbrusati@cal-ipc.org
Gina Skurka, Project Intern
gmskurka@cal-ipc.org
Board of Directors
Steve Schoenig, President (2005)
California Dept. of Food & Agriculture
Alison Stanton, Vice-President (2005)
BMP Ecosciences
Carri Pirosko, Secretary (2005)
California Dept. of Food & Agriculture
Jennifer Erskine-Ogden, Treasurer (2005)
U.C. Davis
Joe DiTomaso, Past-President (2005)
U.C. Davis Weed Science Program
Jon Fox (2005)
California Polytechnic University, San Luis Obispo
Mark Newhouser (2005)
Sonoma Ecology Center
Dan Gluesenkamp (2005)
Audubon Canyon Ranch
Bobbi Simpson (2005)
National Park Service – Exotic Plant Management Team
Jason Giessow (2005)
Santa Margarita/San Luis Rey Weed Management Area
Wendy West (2005)
U.C. Cooperative Extension, El Dorado County
David Chang (2006)
Santa Barbara Agricultural Commissioner’s Office

Given that “invasive species” and “toxics in the environment” are both environmental
concerns, it is no wonder that major groups like the Sierra Club have failed to come to
grips with the complexity. It was notable that the cover article in last May’s Sierra, about
a raft trip down the Colorado to remove saltcedar, mentioned that the author’s crew
used herbicides on the stumps of trees they cut down.
It is important that those who use herbicides respect the concerns of those who do not,
and that these in turn realize that restorationists who do use herbicides do so in the
reasoned belief that their judicious application has an ecological net benefit and does
not put human communities at risk. When either “side” stops giving the motivations of
those with differing opinions the benefit of the doubt, dialogue suffers.
It is also important that we continue to accrue good science on both the intended and
unintended affects of herbicide use for restoration, and that this science be presented
accurately for public interpretation. In a case that shows the potential for misinterpretation, a recent study by University of Pittsburgh biologist Rick Relyea on the lethal
effects of RoundUp on aquatic amphibians has been presented in ways that can easily
lead to the perception that legal, appropriate use of glyphosate formulations kills frogs.
(Terrestrial glyphosate formulations like RoundUp cannot legally be used in an aquatic
setting, while other glyphosate formulations using different adjuvants are labelled for
safe use in aquatic situations, and would be used by any but the most irresponsible
restorationist.)
In a comment passed on to me, an older Oakland resident concerned about herbicides
chided restorationists to “think of the children!” That is precisely what they are doing.
As the recent National Geographic article on invasive species concludes, future generations will find it difficult to forgive us if we fail to address this major problem.

Joanna Clines (2006)
Sierra National Forest
Christy Brigham (2006)
Santa Monica Mountains National Recreation Area
Bob Case (2006)
California Native Plant Society

Affiliations for identification purposes only.
Last year of term noted.

Cal-IPC News
Spring 2005 – Volume 13, Number 1
Editors: Doug Johnson and Elizabeth Brusati
Cal-IPC News is published quarterly by the California
Invasive Plant Council. Articles may be reprinted with
permission. Submissions are welcome. We reserve the
right to edit all work.

2

Cal-IPC News

Spring 2005

On the Cover: Uprooted mustard plants spread
seed by “tumbling” in the wind. Volunteers are
needed to conduct driving surveys to map the
plant’s spread by noting the amount of mustard
cover along California desert right-of-ways.
Mapping protocol, photos of cover classes, and
more information on Brassica tournefortii can
be viewed at www.cal-ipc.org. (Photo Jason
Giessow)

Wildland Weed NewsNewsNewsNewsNews
California Invasive Weeds Awareness
Week is July 18- 24, 2005. Invite local
legislators—county, state and federal—to
view your weed management activities.
What representative could resist a photoop with a weed wrench? The California
legislature is scheduled to be on recess and
most reps will be in their home districts. A
Weed Week poster and a packet of
suggestions for activities are available on
the Cal-IPC website.
AB 577, authored by Lois Wolk (DDavis), passed the Assembly’s Water, Parks
and Wildlife Committee on April 12. The
bill would require the state’s Secretary of
Food and Agriculture and the Secretary of
Resources to develop a statewide plan for
management and control of all invasive
species by Jan. 1, 2007. The bill must now
be heard by the Assembly Committee on
Appropriations.
The National Aeronautics and Space
Administration (NASA) has become the
13th Cabinet agency to join the National
Invasive Species Council (NISC). NASA
will make satellite data, computer modeling and engineering experience available
to NISC. This work is part of the Applied
Sciences Program in NASA’s Science
Mission Directorate, which partners with
public, private, and academic organiza-

Save the Date!

2006 Cal-IPC
Symposium
October 6-8
Chico
Information posted at
www.cal-ipc.org

tions to extend the benefits of NASA
research to innovative solutions for decision
support for applications of national priority.

Researchers using an aircraft flying at the
edge of space measured leaf nitrogen and
water concentration to spot invasive
Myrica faya trees starting to take over
native forests near Hawaii’s Kilauea
Volcano. Study published in Proceedings of
the National Academy of Sciences (March
2005).
Columnists for the National Gardening
Association addressed the issue of invasive
plants in their “In My Garden” regional
reports on February 17, 2005.

Middlebrook Gardens, a garden design/
build firm in San Jose, has begun a “Lose
The Lawn” program directed toward
homeowners. The program extols the
benefits of switching from lawns to “more
natural, efficient and aesthetically unique
options,” and provides information on how
to make the switch. Lose the Lawn also
offers to work with local high school
students.
The Sacramento Bee reported (3/14/05)
that agricultural inspections at ports of

2nd Annual
Photo Contest
Start selecting your best weed
photos for this year’s contest! Categories include:
Best weed impacts shots
Best weed workers shots
Best landscape shots
Best specimen shots
Best weed humor shots
Digital submissions preferred, to
edbrusati@cal-ipc.org.
Deadline September 1, 2005.

entry fell markedly between 2002 and 2004.
The eight percent decrease occurred even as
imports kept rising, and coincided with the
Homeland Security Department replacing the
Agriculture Department at the inspection
stations.

Weed List revision update: 150 plants now
have draft assessments posted at www.calipc.org, with the final 100 coming in July.
Review species you are familiar with and give
us your comments by August 31. The revised
list will be presented at the Symposium in
October . Click “List Revision” from Cal-IPC
home page.
Got year-end money? If your organization
has educational funds that need to be spent
this fiscal year, consider purchasing outreach
materials from www.cal-ipc.org.
Seen the Grass ID CD? Joe DiTomaso’s
Grass and Grass-like Weeds of California
CD ROM has an expert key with a photo
library to help with grass identification.
Available from www.cal-ipc.org.
Board nominations: Got a colleague who
would make an excellent member of the CalIPC Board of Directors? Send 2006 nominations to current Board President Steve
Schoenig at sschoenig@cdfa.ca.gov.

Coming
Soon…
The new Biological
Pollution brochure
describes the consequences of biological
invasions for a general
audience. Targeted
distribution venues are
park visitor centers and
public events.
Special early order price:
$110 per pkg. of 1,000 brochures
www.cal-ipc.org or 510.843.3902
Cal-IPC News

Spring 2005

3

Featur
e
eature

Which W
eeds Dominate Southern
Weeds
California Urban Riparian Systems?
by Brad Burkhart, Burkhart Environmental Consulting, and Mike Kelly, Friends of Los Penasquitos Canyon Preserve
Since the late 1960s there has been a
plant species able to invade and exclude
turnaround in national and state attitudes
native vegetation cover in riparian systems.
towards urban riparian systems. We have
However, unlike accidental runoff that can
moved from a philosophy that viewed such
benefit wetland habitat expansion, plant
systems as either water sources or sewage/
invasions usually decrease habitat values.
stormwater conveyance systems to recognizing Although invasive species may provide
that properly maintained wetland habitats are some habitat values, such as roosting and
essential to maintaining
water purity and wildlife
habitat values. In the
process, riparian habitat
restoration and preservation
have become high priorities.
Urban riparian systems
in Southern California are
rarely natural systems.
Although we often hear that
90-95% of historic California wetlands have been
filled or drained, almost no
perennial riparian systems
existed in Southern California before urban development (Ellis and Lee 1919).
Most drainages were
episodic, flowing only a few
Removing Arundo on the San Diego River. (photo by author)
months of the year during
larger storm events.
Now, many formerly episodic rivers and nesting sites, pollen and nectar for pollinacreeks in the region carry water year-round tors, and foraging opportunities, the
due to over-irrigation of residential and
monocultures these exotic species form
commercial landscaped areas. New small
displace a native habitat with greater
wetlands have sprouted up in finger
diversity of shelter, structure and food for
canyons and arroyos where none existed
native fauna (Ohmart 1982). Additionally,
decades ago, created by this same humansome species like giant reed (Arundo donax)
caused runoff. For example, a USGS water
or tamarisk (saltcedar, Tamarix ramosissima)
flow station on Peñasquitos Creek in San
transpire water at such high rates they may
Diego shows that this once episodic creek
drive the water table below the surface,
became perennial in 1982, persisting since
eliminating surface flow (Sudbrock 1993,
then even through several bouts of
Johnson 1986, Hoddenbach 1987).
drought. This reflects the intense urbanizaFor these reasons, eradication of highly
tion of this watershed that began in the
invasive exotic species and replanting of
1970s and continues today (White and
invaded areas with native wetland species
Greer 2002).
have become primary goals of wetland
Besides a year round water supply,
restorationists. Yet, for the most part, we
urbanization of the landscape has also
possess only a visual and qualitative
introduced many non-native ornamental
understanding of the degree to which

4 Cal-IPC News Spring 2005

various invasive weed species dominate
riparian systems. To the best of the authors’
knowledge, few comprehensive and quantitative surveys of riparian/wetland systems have
been carried out in Southern California.
Therefore, many restorations tend to focus on
the most invasive species such as giant reed,
ignoring other species waiting in
the wings to fill their niche once
we eradicate the most dominant
species.

Mapping a watershed
To address this problem,
Burkhart Environmental
Consulting (BEC) and Kelly
and Associates (K&A) submitted
a successful proposal on behalf
of the Friends of the Mission
Valley Preserve, a non-profit
organization focused on the San
Diego River, to the California
Water Quality Control Board
(RQCB) in late 1999 to utilize
sewer spill fines assessed against
the City of San Diego to map
11.5 miles of freshwater wetland
invasive weeds on the San Diego
River within the city limits. The mapping
used low elevation aerial photos at 50-scale
that were groundtruthed on foot. The areas
of cover were then planimetered off a final
base sheet to determine actual areas of cover
for each weed category.
This project provided clear maps
showing the acreages of infestation of the
major weed species covered by the report for
the City’s river corridor. Significantly, these
maps cover the majority of urbanized
watershed area along this drainage, which has
been designated by the state as a Natural
Open Space Conservancy. This summary
should give the restoration community a
preliminary quantitative assessment of the
amount and extent to which highly invasive
exotic weeds have established in one of
Southern California’s major riparian systems,

and the assessment should be applicable to
other systems in the area.
We selected seven categories of invasive
weed species mapping (Table 1; a more
extensive list of species encountered during
our survey appears in Table 3). Each
category delineates a single weed species,
except broadleaf trees and palms, where
several species were covered under one
mapping category. All of these species were
part of the original project design parameters except castor bean (Ricinis communis),
which was added after it became apparent
during the groundtruthing effort that it
dominated large areas along the river
corridor.
The study area runs from Interstate 5 in
the west (starting about 1 mile from the
ocean) to the Santee City border in the
east, excluding Mission Trails Regional
Park, which has largely eliminated invasive
species within their borders. Approximately
438 acres of wetland habitat were surveyed,
with 65.6 acres or 15% of wetland cover
constituting highly invasive weed species
cover.
Palm trees were divided into large (6%),
medium (37%), small (63%), and seedling
palms. No attempt was made to assess the
size of broadleaf tree species in the mapping project, but some preliminary data on
this subject was obtained from later
eradication efforts. Broadleaf trees were
distributed differently than mapped palm
trees: more large (24%) and medium
(46%) versus small (31%).

Arundo, broadleafs dominate
Two categories of weed cover account
for the majority of weed acreage. By far,
the highest level of cover comes from giant
reed (58% of all exotic weed acreage
mapped). Broadleaf trees account for
another 25%, with the greatest coverage
contributed by Brazilian pepper (10.4%)
and eucalyptus species (9.6%), followed by
Ludwigia (8%), pampas grass, palms, castor
bean, and tamarisk.
This cover is somewhat deceptive,
however, since the numbers of pampas
grass, palms, and tamarisk counted (3,221)
are nearly one third more than the number
of broadleaf trees counted. The number of
palms and palm seedlings (which were
probably undercounted) is over half as
great as all broadleaf trees (1,160 compared to 2,073). Nevertheless, giant reed and
exotic broadleaf trees are clearly the top two
weed types in need of control.

Table 1: Cover of Weed Species Mapped on the San Diego River
Weed species
Giant Reed
(Arundo donax)
Pampas Grass
(Cortaderia selloana)

(All areas)
Acres %Cover Nos.

(City-owned property)
Acres %Cover Nos.

37.95

57.8%

–1

11.33

0.55

0.8%

1,970

0.39

1.9%

6.85

10.4% 649

2.99

13.8%

263

6.27

9.6%

975

1.61

7.3%

164

91

0.25

1.1%

33

51.5%

–1
1,411

Exotic Broadleaf Trees
Brazilian Pepper
(Schinus terebinifolia)
Eucalyptus
(Eucalyptus spp.)
Evergreen Ash
(Fraxinus udhei )
Other Exotic Trees2
Total Broadleaf Trees:

0.63

1.0%

2.48
16.23

3.8% 358
24.7% 2,073

0.88
5.73

4.0%
26.0%

105
565

Palm Trees3
Large Palms
Medium Palms
Small Palms
Total Non-Seedling Palms:
Total Seedling Palms:

0.4
1.37
0.68
2.45
0.07

0.6%
2.1%
1.0%
3.7%
0.1%

37
194
392
623
538

0.25
0.86
0.23
1.34
0

1.1%
3.9%
1.0%
6.1%
0.0%

23
122
121
266
31

2.42

3.7%

–1

1.97

9.0%

–1

0.98

1.5%

91

0.24

1.1%

29

4.97

7.6%

–1

1.01

4.6%

–1

Castor Bean
(Ricinis communis)
Tamarisk
(Tamarix ramosissima)
Ludwigia
(Ludwigia peploides)
TOTALS:

65.62 4 100%

22.01

100%

1

Numbers not counted for these clonal species.
Including: lemon bottlebrush (Callistemon citrinus), California pepper (Schinus molle), Carrotwood
(Cupaniopsis anacardioides), Chinese elm (Ulmus parvifolia), common fig (Ficus carica), myoporum
(Myoporum laetum), oleander (Nerium oleander), other minor species.
3
Mainly Mexican fan palm (Washingtonia robusta) and Canary Island Palm (Phoenix canariensis)
4
Out of approximately 438 acres surveyed in the watershed; this represents 15% of the watershed with
invasive species cover.
2

It is important to note that, when
subsequent restoration work was implemented, greater acreage and numbers of
plants were found to occur on sites than
determined from aerial mapping and
groundtruthing (an underestimation due to
often impenetrable vegetation).
Approximately 20% more acreage of
giant reed was encountered during removal at
the pilot restoration site than was shown on
project maps. Numbers of individual trees
were underestimated by 68% overall, while
trees greater than 12-inch diameter at breast
height were underestimated by almost 300%

(see Table 2). This was surprising because one
would think the larger trees would be the
most apparent on aerial photos. As it turned
out, the single largest canopy exotic tree,
eucalyptus, had no distinct chromatic
signature on the aerials unless its shadow
could be detected falling outside the riparian
area. By comparison, giant reed, Brazilian
pepper, and even castor bean had more or less
distinct signatures on the aerial photos. These
problems were anticipated in some sections of
the initial study and percentage-increase
fudge factors were added for both number
continued page 12
Cal-IPC News

Spring 2005

5

Conference Reports
Summaries contributed by Peggy Olofson,
Elizabeth Brusati, and Wendy West.
The Third International Conference on
Invasive Spartina was held in San Francisco
November 8-10, 2004. The conference
featured presentations on technical research
and control projects from around the world,
including China, Spain, and Tasmania. An
expert panel assessed the treatment strategy
proposed by the Coastal Conservancy’s
Invasive Spartina Project for San Francisco
Bay. More information at www.spartina.org.
A Goat Summit, held January 25, brought
land managers together at Fort Mason in San
Francisco to learn how to achieve their
vegetation management goals using goat
grazing. The program, organized by the San
Francisco Department of the Environment,
included presentations on how goat grazing
works, case studies of different management
situations, and considerations for both goat
providers and clients. Presenters were Dr. An
Peischel (of Goats Unlimited and Tennessee
State University Cooperative Extension) and
Dr. Roger Ingram (Livestock and Natural
Resources Farm Advisor for Placer and Nevada
Counties). The afternoon session was devoted

Ken Moore, 2004 recipient of the Cal-IPC
Golden Weedwrench Award for Land
Manager of the Year, demonstrates the drill
injection method he uses as one of the tools of
the trade at the Eucalyptus control workshop.

6 Cal-IPC News Spring 2005

to group projects designing management
remembered – many staffers were familiar with
plants for different scenarios, including fuel
the issue and remembered the team’s visit from
reduction, riparian restoration, and yellow
last year’s event. Some excellent discussions
star thistle removal.
occurred with legislators and staffers, especially
While goats can be a good tool in some
about creative avenues for funding. Generally,
situations, land managers must define their
attendees felt that the legislators’ staff members
objectives clearly and research prices and
were engaged and interested. Most offices were
goat providers carefully before
hiring a provider. It is important to check references for
providers, to ensure their goats
have experience with the
plants you want to remove.
Some land managers have had
bad experiences with goats
damaging native plants or
spreading invasive seeds, so if
you have never used grazing
before, you should call around
to hear about other people’s
experiences. Damage to nontarget plants can be minimized
by caging the plants, but that
Cal-IPC Boardmember Dan Gluesenkamp with new pal,
is labor-intensive.
Senator Dianne Feinstein at NIWAW-6. Photo Bob Case
If you are interested in
learning more about goat grazing for
interested in signing a “Dear Colleague” letter
vegetation management, Roger Ingram runs supporting for full appropriations of $15
a Browsing Academy through U.C.
million authorized by the Noxious Weed
Cooperative Extension. The next workshop
Control and Eradication Act of 2004. Dan
will be held September near Marysville or
Gluesenkamp and Gina Skurka drafted a letter
Colfax. (Contact Roger at
for California representatives. The letter is
rsingram@ucdavis.edu for more informaposted on the NIWAW website
tion). Several state cooperative extension
(www.nawma.org) as a sample.
departments also publish articles on using
goats for vegetation management.
Control of Blue Gum Eucalyptus in Coastal
California was the topic of a workshop
The 6th annual National Invasive Weeds
organized by the Elkhorn Slough National
Awareness Week took place at the end of
Estuarine Research Reserve’s Coastal Training
February. Eight representatives from
Program at Moss Landing in Monterey County.
CALIWAC (the California Weeds Awareness A follow-up to last year’s workshop on ecology
Coalition) trekked across the country to join and impacts of eucalyptus, this year’s program
weed workers from thirty other states in
featured presentations on planning and
Washington, DC for the week’s events.
implementing control projects, followed by a
Along with agency briefings with USDA
fieldtrip to the Elkhorn Slough NERR.
and Department of the Interior staff, the
Presenters described the need for a biological
crew met with other invasive/exotic plant
assessment to determine when removal of
councils and non-governmental organizaeucalyptus is appropriate, methods of commutions.
nity outreach to build support for removal
Perhaps most importantly, the
projects, techniques for cutting and removing
CALIWACers went to the Hill and met
eucalyptus or killing it in place, and monitoring
with legislative staff in 23 Congressional
after removal. Don Seawater described both
offices to discuss California and nationwide
high-end (garden gazebos) and low-end
weed issues, especially funding for Weed
(mulch) uses for removed eucalyptus wood .
Management Areas through S.144. The
After lunch, presenters described case
team dropped off info packets at 30 other
studies of eucalyptus control efforts in the Bay
legislative offices, covering more than twice
Area and Santa Cruz. During the field trip, Ken
as much ground as in previous years.
Moore described his favorite techniques for
CALIWAC’s message was heard and
eucalyptus removal, and Cammy Chabre led a
walk through an oak woodland restored after

eucalyptus removal.
The Coastal Training Program’s new
website at www.elkhornsloughctp.org contains
presentations from both the 2004 and 2005
eucalyptus workshops, as well as information
on future training programs. In addition, the
Q&A section allows you to submit queries on
eucalyptus to be answered by the CTP staff.
The 2nd Invasive Weeds Awareness Day at
the Capitol, held March 9th in Sacramento,
was a huge success! Organized by the
California Invasive Weeds Awareness Coalition
(CALIWAC), the day included meetings with
agency heads and legislators at the state
capitol. Secretary for Resources Mike
Chrisman and Secretary for Food and
Agriculture A.G. Kawamura spoke to the
standing-room-only audience in the morning.
Both agency heads noted that increased
coordination to stop the introduction and
spread of invasive species was a top priority for
their respective agencies.
Fifty-three weed workers—including a
few stalwarts who traveled from southern
California—attended the afternoon session, in
which in teams met with legislators and/or
staff members in eighty office to discuss Weed
Management Area funding, the California
State Weed Plan, and California Invasive
Weeds Awareness Week. An informational
packet, including position statements and

contact information,
was left with each
office visited as well
as at the 37
additional offices
where we were not
able to set up a
meeting, giving full
coverage at all
legislative offices!
(We covered twice as
much ground as last
year when we met
with 45 offices and
dropped information at 10 more.)
Our message was
heard – even in a
Day at the Capitol participants Bethallyn Black, Bob Case, and Ralph
difficult budget
Kraetsch—all from Contra Costa County—bring information and
climate, attendees
yellow starthistle bouquets to legislators.
reminded legislators
that invasive and
noxious weeds don’t stop spreading. Many
staff. Especially encouraging were connections
legislators and staff members remembered
made with legislators representing urban
CALIWAC from last year, and were glad to see districts, and it was agreed that more emphasis
us returning with silk yellow starthistle
needs to be put on this next year.
bouquets, invasive weed note pads and
Discussions about funding avenues turned
CALIWAC pins in hand.
up several ideas concerning potiential bond
A wrap-up session allowed attendees to
funds, grant access, and road fees—lots for
share some of the great connections made
CALIWAC to follow up on.
during the afternoon, and some of the ideas
that flowed from discussion with legislative

Regulatory Update
EP
A St
atement on P
esticide Applications Near W
ater
EPA
Statement
Pesticide
Water
Summary of January 28 EPA Statement, edited
from info in AquaTechnex online newsletter, at

In recent years, courts have been faced
with the question of whether the Clean Water
Act requires an NPDES (National Pollutant
Discharge Elimination System) permit for
pesticide applications (e.g Headwaters v. Talent
Irrigation District, or “Talent decision”). As a
result, public health authorities, natural
resource managers, and others whose work relies
on pesticides have expressed to EPA their
concern and confusion about whether they
have a legal obligation to obtain an NPDES
permit when applying pesticides registered for
aquatic use to or over waters of the U.S. They
were also concerned about the impact such a
requirement would have on their ability to
accomplish their missions.
EPA’s interpretive statement and proposed

rules are intended to address these concerns
and clarify jurisdictional issues between the
Clean Water Act and the Federal Insecticide, Fungicide and Rodenticide Act
(FIFRA) pertaining to the application of
pesticides. EPA solicited public comment
on an interim statement and guidance in a
Federal Register notice published 8/13/03
and received more than 400 comments
expressing a wide range of views.
The interpretive statement and
proposed rule say that application of a
pesticide to waters of the U.S. consistent
with all relevant requirements under
FIFRA does not constitute the discharge of
a pollutant that requires an NPDES permit
in the following two circumstances:
1. Application of pesticides directly to U.S.
waters in order to control pests. Examples
include applications to control mosquito
larvae, aquatic weeds or other pests.

2. Application of pesticides to control pests
present over or near waters of the U.S., that
results in a portion of the pesticide being
deposited to water.
Clarification of these issues is important
because doubt over a requirement to obtain an
NPDES permit can impede the ability of local
officials to quickly control pests, such as
mosquitos that may carry communicable
diseases like West Nile virus, or invasive species
that may damage natural resources. EPA
indicates that existing regulation for pesticides
under FIFRA adequately safeguard human
health and the enviroment without imposing
undue burden on local governments and
others that rely on pesticides.
Copies of the Federal Register notice that
contains the interpretive statement and
proposed rule are available on EPA’s web site at
.
Cal-IPC News

Spring 2005

7

Tools and T
echniques
Techniques

The Basal Bark Method of
Applying T
riclop
yr Herbicide
Triclop
riclopyr
By Bill Neill, Riparian Repairs and Team Arundo Angeles
As we celebrate the 5th anniversary of Cal-IPC’s Invasive Plants of
California’s Wildlands (UC Press, 2000), I would like to offer some
insights about control methods that were not fully appreciated when
the book was assembled during the late 1990’s. My comments address
basal bark and foliar treatment methods using Pathfinder II and Garlon
4 formulations of triclopyr ester herbicide.

Basal Bark T
or Bean
Trr eatment o
off Cast
Castor

spray one-inch diameter stems from a distance of 3-4 feet without
hitting adjacent stems. For treating large infestations of established
castor bean plants, I sometimes use a backpack sprayer to apply Garlon
4 diluted to 20 percent in diesel oil, as permitted by the Garlon 4
label. Once I tried diluting to 15 percent, but that dilution proved
ineffective.
Not only is the basal bark treatment method quick and easy, it also
limits applicator contact with the plant’s poisonous foliage. The ricin
toxin present in castor bean seeds, foliage, and wood is persistent in the
human body, where one ricin molecule can destroy thousands of
ribosome molecules necessary for protein synthesis. Unlike synthetic,
manufactured compounds, the human heath effects of low-level
exposure to natural poisons such as ricin have not been studied by the
U.S. EPA.
After herbicide treatment, dead trees left standing will topple
within one year and disintegrate to wood fragments over several years.
Some practitioners cut off and bag the seed clusters for disposal, but I
never do. Green unripe seeds should be incapacitated by the herbicide
treatment, and in any case, a persistently viable seedbank will already
be present on the ground under and near the tree canopy from prior
years of seed production. Another advantage of basal bark treatments,
compared to foliar spraying of established large plants, is that the
herbicide is applied beneath the castor bean foliage, without risk of
drift to adjacent native vegetation.

Over the past five years I have treated many thousands of mature
castor bean plants in numerous riparian corridors, stream channels,
natural areas and flood control basins of Los Angeles, Orange and
Riverside Counties, all without felling trees or cutting bark. In the
early 1990s, while organizing volunteer groups to remove tamarisk in
desert areas, I learned that the basal bark method using Pathfinder II is
effective on tamarisk trunks less than about 4 inches in diameter (see
Spring 1997 CalEPPC News). So
Foliar T
Trr eatment o
off
when I started to work professionCastor Bean Seedlings
ally on invasive plants in coastal
Although mature castor bean
watersheds, I wanted to determine
plants can be quickly dispatched by
the trunk diameter limit for
basal-bark treatments, the larger job
controlling castor bean by basal bark
is controlling successive waves of
treatment.
castor bean seedlings that sprout
I discovered that castor bean is
from the persistent seed bank.
highly susceptible to basal bark
Because the seed is relatively large
applications of triclopyr. The largest
and immobile, most seeds produced
castor bean trees that I’ve encounin previous years will remain under
tered in the Los Angeles area—with
the parent tree canopy or short
trunk diameters of 10-12 inches,
distances downslope, sprouting
heights of 15 feet, and crowns 25
initially as dense carpets of seedlings
feet across—are susceptible without
after the parent foliage dies and the
the need for adding frill cuts to the
seeds are newly exposed to sunlight
lower trunk. Sometimes a second
during spring months.
In
the
basal-bark
treatment
method,
applicator
sprays
lowest
12
treatment has proven necessary, and
Spray mixtures of either
to
15
inches
of
bark
around
trunk
and
lower
branches.
Using
if the lower bark is cracked and
glyphosate at 2 percent concentraPathfinder
II
herbicide,
this
16-inch-diameter
castor
bean
trunk
partly detached from the trunk,
tion or triclopyr at 1.2 percent
was treated in 40 seconds at Sepulveda Dam Basin in San
then I spray bark higher than the
concentration (2 percent Garlon 4)
Fernando
Valley.
Photo
courtesy
of
the
author.
lowest 8-12 inches of the trunk.
are equally effective at controlling
But I never need to frill-cut or girdle
castor bean seedlings, but an advantage of triclopyr is that foliar
a castor bean trunk with a hatchet, let alone cut off trunks and limbs
treatment produces visible damage much faster. Whereas glyphosate
completely for a cut-stump application.
causes gradual yellowing of treated foliage over periods of one to several
Usually I use a one-quart finger-trigger spray bottle to apply
weeks, triclopyr causes rapid wilting within several hours or overnight.
Pathfinder II, with the nozzle adjusted to discharge a coarse spray or
During spring months after successive periods of rainfall spaced weeks
straight stream depending on the stem sizes. A large multi-trunk plant
apart, this rapid “auxin response” to triclopyr herbicide allows complete
can be treated by spraying the basal bark from two or three directions
treatment of one generation of seedlings before a second generation
in 20 to 30 seconds. Single castor bean stems up to about 4 inches in
sprouts.
diameter can be killed by spraying just one side of the stem; but on
For foliar treatments of castor bean seedlings using a backpack
larger diameter and multiple trunks, I prefer to spray from two or three sprayer, mixtures of 2 percent Garlon 4 in water do not require
directions. With the nozzle issuing a narrow jet of fluid, it is possible to surfactant or colorant—the combination forms an opaque white

8 Cal-IPC News Spring 2005

emulsion which remains visible on castor bean foliage after application.
Spot treatments are rapid and accurate when using a backpack sprayer
with the nozzle adjusted to issue a coarse spray.

Scot
ch Br
oom LLopping
opping T
rial
Scotch
Broom
Trial
By Mike Taylor, US Forest Service, Eldorado National Forest

Ailanthus and broom
Cal-IPC’s Weed Warriors’ Handbook, published last year, mentions
only the cut-stump method for applying glyphosate herbicide to
broom and Ailanthus (tree of heaven), but the basal-bark treatment
method using Pathfinder II—without any cutting—is much faster and
easier for treatment of broom, and both easier and more effective in the
case of Ailanthus. Like castor bean, Ailanthus has thin bark and is
susceptible to basal bark applications of triclopyr ester herbicide. As
noted by Mike Kelly in the 2001 CalEPPC Symposium Proceedings
(p. 105), girdling or felling Ailanthus, followed by cut-surface
herbicide treatments, is not optimally effective because cutting the bark
triggers abundant resprouting from lateral roots. On trunk diameters
less than about 8 inches, one-time basal bark treatments are usually
effective, using Pathfinder II or Garlon 4 diluted in oil; and on larger
trunks, effectiveness can be inhanced by adding frill cuts in a vertical
pattern, leaving strips of intact bark between the frill cuts.
With its funnel shape, broom is well-suited for basal-bark
treatments, using a finger-trigger spray bottle adjusted to issue a coarse
narrow spray stream of Pathfinder II. Using a wick or brush to apply
herbicide to the basal bark of broom is slow and impractical, in my
opinion, especially where plants are tightly spaced with interlocking
canopies. Using the directed spray method, I have treated dozens of
mature Spanish broom plants at Hansen Dam Recreation Area and
Eaton Canyon Nature Center without harming adjacent native plants.
Typically one or more retreatments is necessary on older, larger plants.

Use of Garlon 4 in riparian corridors
I’ve encountered a widespread opinion that Garlon 4 cannot be
applied in riparian corridors “below the high water mark.” This
opinion may result from a misreading of the Garlon 4 label which
prohibits application to “intertidal zones below the high water mark.”
As confirmed by Joel Trumbo, Environmental Scientist with the
Pesticide Investigations Unit of the California Dept. of Fish and Game
(916/358-2952), Garlon 4 can be applied safely and legally adjacent
to streams and lakes provided that spray drift does not contact surface
water. Only where the herbicide may contact water are formulations
registered for aquatic use required, such as Garlon 3A or Rodeo or
Aquamaster, which all require application by the cut-stem method to
treat woody stems.
As with other ester products, triclopyr ester herbicide has the
potential to volatilize when temperatures are high. Herbicide volatility
is somewhat unpredictable, but applicators should be aware of this
phenomenon and should not apply significant amounts of Garlon 4 or
Pathfinder II during warm weather near sensitive crops like grapes, near
landscaped areas, or near sensitive native trees such as Mexican
elderberry. In coastal areas of Southern California, Ailanthus—which is
dormant through winter months—can be effectively treated during
the typically cloudy weather of late spring or during the cooler days of
autumn. Castor bean can be treated during winter and early spring
months because it retains its tropical foliage through the winter,
provided that temperatures remain above freezing.
The author may be contacted at bgneill@earthlink.net.

The Eldorado National Forest (ENF) botany crew (Annie Walker,
Rosemary Carey, Dirk Rodriguez, and Mike Taylor) and volunteers
from the El Dorado Chapter of the California Native Plant Society and
Eldorado National Forest Interpretive Association (Steve Dowty, Don
Smith, Steve and Shelly Perry, Steve Tyron, Ben Parks, Susan Durham,
Howard Williams, and others) have been lopping Scotch broom
(Cytisus scoparius) at the Traverse Creek Botanical “Special Interest Area”
(SIA) for several years (at least since 1998). The last few years we have
timed most of these treatments for late summer or early fall (August –
October). We began to focus efforts toward late season lopping after
noticing the lack of success (and resprouting) from spring or early
summer treatments, and also after reviewing results of lopping
experiments done in the Georgetown area by Carla Bossard in 1987
and 1988, and published in her 1990 Master’s thesis, “Secrets of an
ecological interloper: Ecological studies on Cytisus scoparius (Scotch
broom) in California.”
It is believed that late season lopping treatments result in fewer
crown sprouts (vegetative regrowth from the lower stem area just above
and below the soil level) because the plants experience maximum
drought stress during this time period and lopping physiologically
affects their ability to produce shoots from latent/dormant buds in the
crown. In Bossard’s treatments, where all plants were lopped at 3 cm (~
1 inch) above ground level, 95-100% of plants treated in March 1988
resprouted, compared to 50% of those treated in May 1988, and 05% of plants lopped in August 1988. In the March and May trials
lopping at 0 cm resulted in fewer resprouters and in all trials lopping at
10 cm resulted in more resprouters.

200
3 LLopping
opping T
rial
2003
Trial
Reports of results from previous late season lopping treatments
(1999-2002) at the SIA were anecdotal and based on random
observations of the previous seasons efforts. Estimates of success
ranged from 75 to 90 percent. In September 2003 ENF botanists set
up two test plots in areas of relatively heavy infestations of Scotch
broom. Site 1 was considered “upland” and was approximately 200
yards from Rocky Canyon Creek, a perennial stream and a tributary to
Traverse Creek. Site 2 was nearby but along the edge of Rocky
Canyon Creek in a slightly more mesic (less xeric) site, but only the last
1-2 feet of the plot’s southern edge was adjacent to the creek and could
be considered riparian. No broom plants had yet established in this
“riparian” zone, where they would not be expected to experience the
same degree of drought stress as broom growing on upland sites.
Neither site had been previously treated.
Both plots were flagged off and lopped on September 30, 2003.
Great care was taken to lop every broom plant in the plot, and efforts
were made to lop the stem(s) as close to the soil as possible. Site 1 was
approximately 45 x 30 feet and 348 broom plants were lopped. Site 2
was smaller, about 45 x 20 feet, and 104 broom plants were lopped.
These sites/plots were then evaluated on September 21, 2004. The
sites were carefully searched, sometimes on hands and knees, for
resprouts, seedlings or small broom plants that may have been missed
in 2003.
…continued page 10
Cal-IPC News

Spring 2005

9

Red Alert

Japanese Knotweed (Polygonum cuspidatum) and other knotweeds
by Elizabeth Brusati
Knotweeds are not yet widespread in California, but they invade
riparian areas around the world and should be on the radar screen of
California weed workers. The three species present in California are
Polygonum cuspidatum (Japanese knotweed), P. sachalinense (giant or
Sakhalin knotweed), and P. polystachum (Himalayan knotweed). Of these,
Japanese and giant knotweed are the most invasive. According to Dr.
Mandy Tu of The Nature Conservancy’s Wildland Invasive Species
Program, knotweeds are found in the Pacific Northwest in habitats similar
to areas in California, so it is likely they could explode here as they have
there. They need soil moisture, preferring to colonize riparian sites and
moist waste places. Knotweeds typically require some form of natural or
human-caused disturbance to open space for establishment, and are often
found along the edges of riparian forest or on stream-scoured cobble bars.
Knotweeds are thought to have escaped from garden plantings in the
northwestern U.S. (If you see knotweeds for sale in your local nursery,
alert the owner to the problems they cause in wildlands and contact CalIPC.) They are clumping perennials with coarse foliage, hollow stems, and
creeping rhizomes. Japanese knotweed rhizomes can penetrate 2 inches of
asphalt and can generate new shoots even when buried under 1m of soil.
Once they escape, they can take over riparian zones. Giant and Japanese
knotweeds can grow 15-20 feet tall in one growing season, forming a
dense network of rhizomes, and producing woody stems that persist from

year to year. All three species form dense stands that exclude other
species. Lauren Urgenson, Ph.D. student at the University of
Washington, has found that increases in knotweed density correlate
with declines in herbaceous species, shrubs, and tree seedlings as
well as reductions in both quantity and quality of stream leaf litter
used by aquatic insects.
The Nature Conservancy has knotweed control programs in
both Washington and Oregon, in addition to several working
groups in the Pacific Northwest that focus on these species. TNC
also has brochures, posters, and postcards in both printed and
electronic formats for distribution. For info on management and
control of knotweeds, contact Doug Kreuzer at the Portland Area
Preserves with TNC-Oregon (dkreuz@tnc.org or 503-802-8100)
or Heather Rogers with the Skagit River Project for TNC-Washington (hrogers@tnc.org or 206-890-5417). P. sachalinense and P.
cuspidatum are being reviewed for the revised Cal-IPC Invasive Plant
Inventory. If you have information on these species in California,
please contact the author at edbrusati@cal-ipc.org.
For more information:
TNC Element Stewardship Abstract: tncweeds.ucdavis.edu/esadocs/
polycusp.html
King County, WA, Weed Alert: dnr.metrokc.gov/weeds/brochures.htm
The Knotweed Page: http://www.knottybits.com/Knotweed/

Japanese knotweed invading riparian areas in the Pacific Northwest.
Photos John Randall/The Nature Conservancy

Broom lopping, cont’d…
At Site 1, we found only 12 resprouts and seven small seedlings,
some of which were likely missed during the initial treatment, for a
resprout rate of 3.5% and an effective control rate of 96.5% effective. At
Site 2, we found seven resprouts and 20 seedlings, for a 6.7% resprout
rate and a 93.7% control rate. (The new seedlings and the small broom
plants that were missed in 2003 did not figure into the calculation. All of
these plants were pulled or lopped at the time of the 2004 monitoring.)
Thus the late-season lopping proved extremely effective at limiting
resprouts and minimizing follow-up requirements.

10 Cal-IPC News Spring 200
5
2005

It is expected that new seedlings will continue to appear for
many years, since Scotch broom seeds remain viable for decades.
The good news is that due to the lack of soil disturbance in these
plots (and in the SIA in general) the numbers of seedlings are
expected to diminish over time as the seed bank diminishes and/or
becomes buried under organic litter/duff. Of course maintenance of
the plots and of other treated areas in the SIA must continue in
order to prevent new seedlings from maturing to flowering age (as
young as 3 years old) and renewing the seed bank.
Contact the author at mtaylor@fs.fed.us.

Volunteer Ste
war
dship
Stew
ardship

Herbicides and creek restoration focus of Oakland debate
By Karen Paulsel, Friends of Sausal Creek

Critic’
w ar
ds
Critic’ss Choice A
Aw
ards

Why would a creek restoration group draft an herbicide resolution? Friends of Sausal Creek (FoSC), in Oakland, recently did just
that, and this article provides background for other communities facing
a similar situation.
We started the 10-month process of passing an herbicide
resolution after much internal discussion about the role of herbicides in
restoration work. Our watershed has nearly the whole horror show of
the Bay Area’s woody, resprouting invaders, including eucalyptus (at
least two species), acacia (two species), elm, broom, gorse, blackberries
(two species), holly, and cotoneaster. We had decided that, in some
cases, the benefits of a cut-stump treatment with herbicides could
outweigh risks. For one, our watershed has so many rampant invasives,
they outgrow our current control efforts. Also, many are on steep land
where it is impractical or inadvisable due to erosion potential to remove
woody species. However, we decided that other herbicide use, like
foliar spraying of the great ocean of ivy and Cape ivy that engulfs
much of our urban-forest understory, was out of the question.
As brief background, the 2,656-acre Sausal Creek watershed runs
though the center of Oakland, from the hills above Montclair, across
the Hayward Fault, through the Diamond and Fruitvale districts to the
southern tip of Alameda. The Friends of Sausal Creek operate restoration projects in six of the major plant communities in the watershed, as
well as an education program involving 350 school children per year in
hands-on environmental science education. Our native plant nursery
grows stock from locally-collected seeds and cuttings, and provides
them to other creek groups, restoration projects, and school gardens in
exchange for work in the nursery.
The impetus for the herbicide resolution grew from the Oakland
hills firestorm of 1991. Other funding for vegetation management in
the Oakland hills had dried up, so in 2004, voters in the hills approved an assessment district. The taxes fund fuel reduction on the
1,000 acres of city-owned parks and other properties in the district,
plus additional services. Oakland has a so-called IPM (Integrated Pest
Management) policy, which is actually a ban on herbicides, with major
exemptions, such as golf courses (800 pounds of herbicide were
applied to city golf courses last year), median strip spraying (they’ve
been caught spraying Roundup in the rain!) and the rose garden.
Unfortunately, the vegetation management program run by the
Oakland Fire Department does not fully understand IPM. With
woody, invasive, stump-sprouters, you need to outwit the stump. Since
the 1991 firestorm in the Oakland hills, crews have repeatedly cut
hillsides of broom, only to have them resprout, and the patches have
expanded as the seeds spread. CDF crews have cut one hill of eucalyptus several times. The citizens’ advisory board appointed to allocate the
district’s funds was eager for change after seeing the same vegetation
recut year after year.
The Friends of Sausal Creek knew that we lacked the political
clout to change the herbicide policies of the city on our own, and the
fire issue provided a suitable avenue for controlling invasive woody
weeds in the watershed. Under the leadership of Sue Piper, policy
analyst for Councilmember Jean Quan, Friends of Sausal Creek worked

with city employees and
Wildfire District board
members to draft the
proposed resolution.
The language went
through many revisions,
faced a more restrictive
draft from another
councilmember, and an
assault from the City
Attorney, who wrote a
press release warning
that Oakland could be
sued by workers and
citizens for causing
cancer. The resolution
Volunteer participating in a Sausal
language was finally
Creek workday. Photo Friends of Sausal
approved, with
Creek
compromises, to require
that studies be done before the council approves the use of herbicides.
After a series of meetings that drew a surprising amount of
newspaper and television attention (and many public comments at
meetings), the Oakland City Council approved a resolution on April 5
to prepare a vegetation management plan and IPM documents, and to
do an environmental review of use of herbicides on invasive,
resprouting non-native species. Once the documents are ready, the
council will review them, and vote on the use of the specified herbicides on the species studied. Many homeowner groups endorsed the
resolution, with support also from Cal-IPC, the Invasive Exotics
Committee of the California Native Plant Society, and local creek and
restoration groups. The major opposition came from a loose coalition of
chemically-sensitive individuals and their organizations, who wanted
absolutely no herbicide use. The Sierra Club opposed all spraying, even
from “spritzer” bottles, and opposed herbicide use on any edible plants.
The resolution allows only cut-stump application to invasive,
resprouting, non-natives trees and shrubs, plus pampas grass, in the
context of an IPM plan that gives preference to non-herbicide
treatment. Only glyphosate and triclopyr based herbicides can be used,
and only painting or hand-application is allowed. Under this resolution, herbicides cannot be used near landscaped or developed areas. We
are especially concerned about herbicide use near the creek, because it
supports a small population of rainbow trout, and we know that the
surfactants in some herbicide formulations can be lethal.
Friends of Sausal Creek hopes this resolution provides a first step
in the IPM education process for the wildfire district—matching
methods to the plant species and terrain, timing treatment for greatest
long-term success, and helping protect rare plants, nesting birds, and
other sensitive fauna.
For more information:

Contact the author at kpaulsell@pacbell.net.
Cal-IPC News

Spring 200
5
2005

11

continued from page 5

other public
Table 2: Pilot Project Tree1 Removal Counts Vs. Mapped
institutional
Large
Med.
Small
Total
and acreage of certain species.
ownership
DBH: (>12”) (6-12”) (1-6”)
The quantities shown in Table 1 are
usually makes
Total Trees Mapped:
9
44
35
88
therefore probably underestimated; however,
restoration more
Total Trees Removed:
35
68
45
148
they do give us a fair assessment of the degree
difficult. Out of
Portion identified by mapping
26%
65%
78% 59%
to which these species have invaded this
65.62 acres of
Increase found during restoration
289% 55%
29%
68%
system. Although the amount of weed
invasive weeds
infestations will vary by species and extent in
1
mapped, 34%
includes palms, but they were only a minor part of infestation, so mostly broadleaf.
other Southern California wetland systems,
fell on Citywe anticipate that the species covered by this
than 14 major and minor wetland restoration/
owned property. Management jurisdiction
survey will continue to be the main invasive
mitigation projects have taken place within
for this property is divided between four
exotic weed species in all such systems. Our
the area over the last 15 years. However, the
different City departments (Park & Recrework in other drainages in San Diego supports
only one of these sites that had consistently
ation, Transportation, Real Estate Assets, and
this conclusion.
resisted reinvasion by the most pernicious
Water). This is important because each
species was the FSDRIP project that has a
department has different management
Interpretation of findings
funded, comprehensive, long-term managedirectives, and money available for habitat
One major finding of this study is that
ment plan. This further supports the idea of
restoration by one department is not always
exotic broadleaf and palm tree species are the
masterplanning weed eradication efforts
easily used on another department’s managesecond most dominant category of riparian
within watersheds and providing permanent
weeds after giant reed. This is important since ment area.
maintenance funds for their long-term
As anticipated, exotics were not evenly
relatively few if any riparian habitat restoramanagement in urban drainages.
tions along the San Diego River have included distributed throughout the project area.
In conclusion, this study represents a first
Ornamental trees, for example, had their
non-native tree species for removal, nor,
but
important step in developing a more
highest infestations near the lower reaches of
except for a few projects implemented by the
objective
idea of which species are significant
the river, while areas dominated by castor
authors, do most other riparian mitigation/
in
riparian
invasions in Southern California.
bean were largely localized in only two
restoration projects in Southern California to
We
hope
it
will serve as a planning tool for
stretches of the study area. In addition, it was
our knowledge.
focusing
restoration
funding.
found that where funding was in place for
A second interesting finding is the degree
long-term management of former mitigation
to which weed infestations fall under City or
For more info on this project, contact Brad
sites, there was very low reoccurrence of
non-City control, because private property or
Burkhart at b.burkhart@attglobal.net or visit
invasive weed species even
.
when they had dominated
Table 3: Invasive Plants Mapped in Study Area the area before mitigation
References:
installation (e.g. the Citygiant reed (Arundo donax)
managed First San Diego
Anderson, B.W. and R.D. Ohmart, 1982.
Cape ivy (Delairea odorata)
Revegetation for wildlife enhancement along the
River Improvement Projectcastor bean (Ricinis communis)
lower Colorado River, Final report to the U.S.
FSDRIP).
climbing milkweed (Sarcostemma cynanchoides ssp. hartwegii)
Bureau of Reclamation, Boulder City, Nevada.
Another important
fennel (Foeniculum vulgare)
Barrows, C. 1998. The debate over tamarisk: the
finding of the surveys was
ludwigia (Ludwigia peploides)
case for wholesale removal. Restoration & Managediscovery of small infestament Notes 16: 135-139.
pampas grass (Cortaderia selloana)
tions of two well-known,
sticky eupatorium Ageratina adenophora)
Ellis, A.J. and C.H. Lee. 1919. Geology and ground
highly invasive species: Cape waters of the western part of San Diego County,
perennial pepperweed (Lepidium latifolium)
California. U.S. Geological Survey., Water Supply
ivy (Delairea odorata), and
tamarisk (Tamarix ramosissima)
Paper 446.
perennial pepperweed
Virginia creeper (Parthenocissus quinquefolia)
Hoddenbach, g. 1987. Tamarix control. Tamarisk
(Lepidium latifolium). Their
Broadleaf Trees
control in southwestern United States. Cooperative
numbers were too small to
bottlebrush (Callistemon citrinus)
National Park Resources Studies Unit, Special Report
note on the tables, but their
no. 9:116-125.
Brazilian pepper (Schinus terebinthifolius)
discovery has led to efforts to Johnson, S. 1986. Can tamarisk be controlled? The
California (Peruvian) pepper (Schinus molle)
eradicate both before they
Nature Conservancy News. Arlington, Virginia.
carrotwood (Cupaniopsis anacardioides)
October-November.
can spread.
Chinese elm (Ulmus parvifolia)
Finally, it was interesting Sudbrock, A. 1993. Tamarisk control: I Fighting
edible fig (Ficus carica)
to examine the occurrence of back-An overview of the invasion, and a low-impact
eucalyptus (Eucalyptus spp.)
way of fighting it. Restoration & Management Notes
weed species in areas where
evergreen ash (Fraxinus udhei)
11: 31-34.
prior mitigation/restoration
myoporum (Myoporum laetum)
White, M.D. and K.A. Greer. 2002. The Effects of
projects had been impleoleander (Nerium oleander)
Watershed Urbanization on Stream Hydrologic
mented, and where they had Characteristics and Riparian Vegetation of Los
Palms
theoretically been eliminated Peñasquitos Creek, California. Conservation Biology
Mexican fan palm(Washingtonia robusta)
prior to permit release. More Institute.
Canary Island date palm (Phoenix canariensis)

12 Cal-IPC News Spring 2005

New and Contributing Members
Thank you for your generous support! This list reflects donors and new members since the last newsletter.

Donations and Contributing Members
June Bilisoly (Portola Valley)
Ron Felzer (Merritt College, Oakland)
Dorothy B. Hunt (Pacific Grove)
Anna Schrenk (Twentynine Palms)
Georgia Stigall (Native Habitats, Woodside)
Swimmer Family Foundation
Wendy Tokuda (KRON, Oakland)
Edward Tuttle (UCLA, Los Angeles)
Stan Weidert (Shingletown)

New Members
Paul Aigner (UC Davis – McLaughlin Preserve, Lower Lake),
Wolfram Alderson (San Francisco), Paul Amato (SF Regional Water
Quality Control Board, Oakland), Alac Anderson (Santa Barbara
Natives, Gaviota), Ed Armstrong (Foothill Associates, Rocklin),
Laura Baker (CNPS – East Bay Chapter, Berkeley), Betsy Wanner
Bikle (Mill Valley Streamkeepers, Mill Valley), Alison Blume (Blume

& Buffalow Garden Design, San Rafael), Curt Boutwell (KCI
Environmental, Inc., San Luis Obispo), Bonnie Brooks (Garden Club
of America, Carmel), Janet Canterbury (Santa Cruz Island Plant
Restoration Project, Los Angeles), Mary Clifford (Cotati), Stephanie
Curtis (Curtis Horticulture, San Jose), Holly Damiani (Sacramento),
Susan G. Duncan (Oakland), Annette Floyd (San Francisco), Toni
Garnett (Vicente Hillside Foundation, Berkeley), Tom Griggs
(Sacramento River Partners, Chico), Valerie Haley (Native Vegetation
Network, Santa Cruz), Wynne Hayakawa (San Francisco), Curtis
Kendall (Audubon California, Mayacamas Mountains Sanctuary,
Healdsburg), Paul Kilburg (San Diego Park & Rec Dept., Open Space
Division, San Diego), Tanya Kucak (Palo Alto), Betty Kunze (San
Bruno), Maria Lum (LSA Associates, Inc., Riverside), Ingrid Madsen
(Berkeley), Lawrence Maxwell (San Francisco), Steve McGonigal (WA
State Noxious Weed Control Board, Olympia), Tony Norris (Napa),
Greg Scott (Newark), Heidi Stewart (Master Gardeners, Sebastopol),
Sarah Swinerton (Garden Club of America, Woodside), Mark Tucker
(Wildlands, Inc., San Diego), Barb Weaver (Burlingame)

Horticulture

Cal-IPC comments on APHIS plant importation rules
After review of the proposed rulemaking (Docket No. 03-069-1),
Cal-IPC submitted the following comment regarding phytosanitary
restrictions on plant importation. The U.S. Department of
Agriculture’s Animal and Plant Health Inspection Service (APHIS) is
considering substantial revisions to the regulations known collectively
as Quarantine 37. In the past, these were intended to exclude pests and
pathogens inadvertently imported via nursery stock and seeds. APHIS
recently asked for broad input related to “plants for planting,”
including possible pest problems from the plants themselves. For the
first time, some of these revisions could address the known and
potential invasiveness of imported plants and seeds, e.g., by establishing a list of plant taxa that would be excluded from import pending
risk evaluation and approval.
The Nature Conservancy submitted a 36-page document with
numerous detailed suggestions. Cal-IPC’s letter—quoted below—
responded directly to two specific issues raised by APHIS: (1) whether
all shipments should require accurate scientific labelling of contents,
and (2) whether formal “pest risk assessments” should be required for all
new taxa requested for import, or whether the assessments should only
be required for plants for which literature indicates a problem already
exists.
“The California Invasive Plant Council (Cal-IPC) is dedicated to
protecting California natural areas from invasive plants. Our members
comprise land managers, researchers, volunteer restorationists and
concerned citizens. Horticulture is the top pathway for introduction of
invasive plants in California historically, and we have an active working
partnership with the horticultural community to deal with invasives

still in the trade. We are encouraged that APHIS is considering how to
strengthen programs for preventing importation of invasive plants.
“We support requiring shipments of plants for planting to list their
contents using accurate scientific names. This will be a cornerstone of
tracking and monitoring problem species.
“We support development of a comprehensive screening protocol
for proposed new importations. This protocol should be science-based
and transparent, and should have regular public review. We understand the balance that must be struck between allowing relatively
unimpeded importation of safe plants while screening out invasive
plants. We encourage APHIS to be conservative in protecting U.S.
natural areas from invasive plants. Pest risk assessments (PRAs) should
be required for all new plants proposed for importation, as spelled out
in Option 1. A clear screening protocol should streamline the PRA
process so that it does not result in undue delay for importers.
“While we respect the needs of nurseries and gardeners, and want
to avoid any unnecessary restriction on plant importation, we strongly
support measures that account for the significant ecological and
economic risks to native species and ecosystems posed by introduction
of invasive plants through the horticultural trade.”
Thanks to the Union of Concerned Scientists for helpful background
information, and to Cal-IPC Boardmember David Chang (Santa
Barbara County Agricultural Commisioner’s Office) and Clare Aslan
(U.C. Davis) for assistance with policy analysis.
Cal-IPC News

Spring 2005

13

Readings &
Resources
Website: The Nature Conservancy’s Invasive
Species Initiative announces the new Weed
Information Management System (WIMS).
This application helps managers keep track of
their weed locations, inventory and monitoring data, and allows them to share information with others working on invasive plants.

Handy tool: An anonymous weed warrior
came up with this handy, do-it-yourself
herbicide dauber. Simply dump out the
contents of a bottle of Shoe Scuff Cover ($3
at any grocery store) and refill the bottle with
herbicide. The bottle is designed to release its
contents only when the foam sponge on the
end is pressed against a surface—no pressure,
no fluid. It comes with a plastic, snap-on lid
that prevents accidental discharge when you
carry the bottle in your pocket. Makes small
cut-and-treat jobs very easy.
Publication: The final report from the
workshop “The Use of Fire as a Tool for
Controlling Invasive Weeds,” held last year in
Nevada, is available on the Cal-IPC website.
The report covers risks and challenges, control
effectiveness of prescribed burns on invasive
weeds, integrating burning with other control

techniques, effects on plant communities and
on soil properties.
Publication: Proceedings from the 2004 CalIPC Symposium are now available. Copies
were mailed to Symposium attendees. Printed
copies may be ordered for cost and shipping
($10) from Cal-IPC. A pdf version is posted
on our website, which also contains Symposium presentations, posters, and working
group notes.
Presentations: PowerPoint presentations from
the Transportation Research Board Invasive
Species Workshop, held January 9, 2005 in
Washington, DC, are posted online at

Online database: The Center for Invasive
Plant Management has developed an online
Restoration Resource Database to allow land
managers to search for literature, books,
handbooks, and web sites on restoration,
particularly related to invasive species.
References from federal and state agencies,
journals, conservation organizations, and
others have been consolidated into one easyto-access online database.

Article: National Geographic magazine
featured invasive species in its March 2005
issue. The article, “Attack of the Alien
Invaders,” describes consequences of invasive

species around the world and includes a page
of maps entitled “Global swarming.” National
Geographic does not sell reprints of individual articles, but back issues can be ordered
through their website.

Television series: National Geographic also
produced a four-part series entitled “Strange
Days on Planet Earth,” broadcast on PBS
April 20 and 27. The first episode covered
invasive species; other topics include global
warming, removal of top predators, and water
quality. The PBS website has activity guides
for educators. DVDs of the series can be
ordered from on-line booksellers for approximately $35.

Report: The Invasive Species Specialist Group
has published “100 of the World’s Worst
Invasive Species,” available for downloading
in English, French, and Spanish.

Website: A coalition of private and public
sector organizations has taken a step forward
in the battle against the globally spreading
fungal pathogen Phakospora pachyrhizi (Asian
soybean rust) by creating a comprehensive,
freely accessed on-line soybean rust information center.

Homeowners’ Association Uses Cal-IPC List
to Discourage Invasive Plants
By Mark Jacobucci, The Irvine Company
The custom home design guidelines at the
Irvine Company’s Crystal Cove Community
include a link to Cal-IPC in their landscape
section, so that homeowners may readily access
updated invasive plant lists to determine
which plants are considered invasive and
could be harmful if they spread into the
adjacent open space. Homeowners are
discouraged from using such plants on their
lots, and these plants are the targets of
ongoing maintenance by the landscape
maintenance company in common areas.
Crystal Cove is a luxury home development located along Pacific Coast Highway,
midway between Laguna Beach and Corona

14 Cal-IPC News Spring 2005

Del Mar. It is surrounded by permanent open
space, including Crystal Cove State Park, Los
Trancos Canyon, and Muddy Canyon. The
community landscape, while composed
mostly of “well-behaved” ornamentals, also
includes significant areas with native
plants, especially along its outside edges and
interior open space corridors.
The design guidelins are not as strong as
they could be if we had specific provisions on
the CC&Rs (covenants, conditions and
restrictions), but in a way we do have indirect
CC&R provision. We determine the plant
species to be used or removed in all our fuel
modification zones according to the approved
Orange County Fire Authority plant list.
This list has been vetted through the resource

agencies (who are concerned mainly with
screening for invasive qualities) and contains a
mandatory invasives removal component.
However, even if we were to get the
language into the CC&R’s the far greater
white elephant is the tremendous weed bank
on the county and state park land across the
canyons. The agencies simply do not have the
resources to get after them. Our homeowners
are a minuscule source compared to these
surrounding areas. At any rate it’s a start and
better than not trying.
Contact the author at
MJacobucci@irvinecompany.com.

The WILDLAND WEED CALENDAR
Know of an event that should be posted here?
Please contact dwjohnson@cal-ipc.org.

Symposium on Trophic and Guild Interactions in Biological Control

45th Annual Meeting of the Aquatic Plant
Management Society

May 8-11, 2005

July 10-13, 2005

2nd New England Invasive Plant Summit

Magog, Quebec, Canada

San Antonio, Texas

September 17-18, 2005

Joint meeting of International Organization for
Biological Control – Neartic Regional Section
and Biocontrol Network of Canada.

Framingham, Massachusetts

California Invasive Weeds Awareness Week

Contact L. Levesque, University de Montreal at
biocontrol-network@umontreal.ca

July 18-24, 2005

Convened by Invasive Plant Atlas of New
England and New England Invasive Plant
Group

Invasive Plants in the Mediterranean Type
Regions of the World

Invasive Plants: Perspectives, Prescriptions,
and Partnerships

May 25-27, 2005

August 16-17

Montpelier, France

University of Pennsylvania, Philadelphia

An international workshop organized by the
The World Conservation Union (IUCN),
Center for Mediterranean Cooperation,
Mediterranean Botanic Conservatory, the
Council of Europe and the European and
Mediterranean Plant Protection Organization.

Email jlm@pobox.upenn.edu

Invasive Plant School

Contact R.S. Melnicoe, UC Davis,
530-754-8378

June 15-16, 2005
San Diego
Taught by Carl Bell and Nelroy Jackson, this
popular workshop features an overview of weed
control with special emphasis on herbicides.
Contact Carl E. Bell at (858) 694-3386 or
cebell@ucdavis.edu.

See page 3 for information.

North American Weed Management
Association, 13th Annual Conference
September 26-29, 2005
Manhattan, Kansas
Contact Mike Friesen, 620-873-8730

Western Regional IPM Symposium

7th Biennial State of the Estuary Conference

“Water, Wildlife & Pesticides in the West:
Pest Management’s Contribution to Solving
Environmental Problems”

Oakland, CA

Portland, Oregon

Conference will focus on connections
between the watershed, delta, and San
Francisco Bay, with sessions relating to habitat
restoration, estuarine water supplies, and
water quality.

8th International Conference on the
Ecology and Management of Plant Invasions

October 4-6, 2005
Poster abstracts due July 15

September 5-12, 2005

Cal-IPC Symposium

University of Silesia in Katowice, Poland.

October 6-8, 2005

California State University, Chico
This year’s theme is “Prevention Reinvention:
Protocols, Information and Partnerships to
Stop the Spread of Invasive Plants,” focusing
on early detection techniques and partnerships to prevent plant invasions.

Quotable:

“Invasives aren’t like

other forms of pollution. They
don’t stop spreading when you stop releasing them. They grow.

”

Dr. David Lodge, ecologist, University
of Notre Dame, in “Attack of the Alien Invaders”,
National Geographic, March 2005

“Scotch broom is
”

as invasive as it is beautiful. It’s like a

friendly dog that bites.

Kim Haworth, National Gardening
Association columnist (Northern California),
Feb. 17, 2005. www.garden.org

California Society for Ecological Restoration
(SERCAL) Annual Conference
October 19-22, 2005
Bass Lake, CA
Topics include restoration project funding,
linking classroom training to the field,
restoration and ranching, and more. Abstract
deadline June 24.

Cal-IPC News

Spring 2005

15

Cal-IPC Membership Form
We’re working to protect California’s wildlands from invasive plants—join us!
Cal-IPC’s effectiveness comes from a strong membership, including scientists, land managers, policy makers, and concerned citizens. Please
photocopy the form below, complete, and mail with your payment. Additional donations are always welcome to support our projects; we are a
501(c)3 nonprofit organization, and donations beyond regular membership rates are tax deductible.
Individual
Regular
$35
Family
$60
Contributing
$75
Life
$1,000
Joint Cal-IPC/SERCAL
$55
Joint Cal-IPC/CNGA
$70
Cal-IPC/SERCAL/CNGA
$95
Student/Volunteer
$15

Institutional*
Regular
$150
Contributing
$300
Patron
$600
Sustaining
$1,000
Small company
or Nonprofit
$100
* Institutional memberships receive
multiple newsletter subscriptions
and Symposium discounts. Visit
www.cal-ipc for details.

Ways to join:
Mail: send this form with check (made out to “Cal-IPC”) or credit card
info to Cal-IPC, 1442-A Walnut Street #462, Berkeley, CA 94709
Fax: fax form with credit card info to 510/217-3500
Email: send contact and credit card info to dwjohnson@cal-ipc.org
Phone: call us at 510/843-3902 and provide contact and credit card info

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