P.O. Box 5274
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Poster prepared by:
Channel Maintenence Coordinator
St. Paul District, U.S. Army Corps of Engineers Channels and Harbors
431 Northshore Drive
PO Box 397
Fountain City, WIÂ 54629
A workgroup of Wisconsin natural resource professionals with experience in reed canary grass control have been meeting since the fall of 2005 to develop materials to aid landowners and land managers with guidelines for the control of this invasive grass in Wisconsin wetlands. Information generated by the group include a table of available control techniques along with a companion prescription guide that provides information on how to set up a management control plan using a combination of practices and timing of treatments that's tailored to specific site conditions. A third table includes plant species and recommended seed mixes that will compete with Reed Canary Grass (RCG).
Reed Canary Grass Management Manual (PDF, 2MB)
This guide is the most comprehensive manual available and includes information from the latest research and anecdotal information
Herbicide Selection (PDF, 23 KB)
The following is an abridged version of Dr. Mandy
Tu's study on reed canary grass. References to the paper follow.
Reed canary grass is a very important invasive plant in Wisconsin
and nearby states, and its eradication is especially difficult.
It ranked #1 in importance in IPAW's survey of invasive plants.
Reed canarygrass (Phalaris arundinacea - RCG) is a perennial,
cool-season, rhizomatous plant in the grass family (Poaceae / Gramineae)
that grows successfully in northern latitudes. Its creeping rhizomes
often form a thick sod layer which can exclude all other plants.
Its upright stems grow to 2 meters tall from the rhizomes, and its
flat leaf blades measure up to 0.5 m long by 2
cm. RCG has open sheaths, hollow stems, small clasping auricles
and membranous ligules. Reed canary grass can grow on dry soils
in upland habitats and in the partial shade of oak woodlands, but
does best on fertile, moist organic soils in full sun. It is a major
problem in natural wetlands, including marshes, wet prairies, sedge
meadows, fens, stream banks, and seasonally wet areas. It also grows
in disturbed areas such as bergs and spoil piles. These stands exclude
and displace desirable native plants. Areas invaded by reed canarygrass
may be of little use to wildlife (Hoffman & Kearns, 1997). Human
disturbance and alteration of water levels encourage reed canarygrass
RCG can reproduce vegetatively by its rhizomes and rhizome fragments,
as well as sexually by its abundantly produced seed. Although each
inflorescence can produce approximately 600 seeds, it probably has
a low successful establishment rate from seeds, especially within
dense infestations. Most plants and recurring populations of RCG
develop from rhizomes. RCG seeds can be dispersed in animal fur,
on human clothing or on automobiles. The most common vector for
RCG seeds and rhizome fragments however, is probably dispersal by
water. RCG seeds have a relatively low rate of germination, and
do not germinate in dense shade. Seedlings are susceptible to prolonged
flooding, prolonged drought, and do not appear to be highly competitive
with perennial native species. Established populations can survive
prolonged drought and can survive over one year of flooding, especially
if parts of the plant are not submerged.
Prevention of new invasions is the most efficient and cost effective
method of invasive species management and control, and the prevention
of new RCG infestations are no exception to this rule. Recent research
completed in Wisconsin and Minnesota have shown that when levels
of available soil nutrients (such as nitrogen) are reduced via carbon
enrichment, a native sedge, Carex hystericina, is able to
competitively suppress the growth of RCG. Sustaining a mosaic of
microtopographies (by preventing sediment accumulation) facilitates
native species richness, and maintaining complex herbaceous canopies
also work to prevent RCG infestation, since RCG seed germination
is dependent on amounts of light penetration.
Isolated plants or small patches of RCG can successfully be removed
by digging out and removing the entire root mass. Removal is easiest
when the soil is moist. Be sure to remove all rhizomes and roots,
as small rhizome fragments can resprout. Properly dispose of plant
material, since rhizomes and stems can develop new roots if inundated,
or if kept in contact with moist ground. Be sure to follow-up to
catch any resprouted stems.
Mowing or cutting (using a mower, brush cutter, weed eater, tractor-drawn
mower, machete, etc.) by itself will not kill RCG. In fact, if RCG
is mowed only once or twice per year, it actually stimulates additional
stem production. Continued mowing (5x or more per year) for 5 to
10 years is reported as successful in controlling RCG, but this
has not been demonstrated on a large scale.
Mowing can be used in combination with another control method,
such as a subsequent herbicide application, for good control. Additionally,
mowing prior to or at the onset of flowering can eliminate seed
set for that year. So, you can choose to mow RCG for several years
to eliminate the seed bank, and then a final mow followed by herbicide
application to eliminate mature RCG. Mowing can also facilitate
the installation of shade cloth, or be used as a pre-treatment for
tillage, since it will remove or break up the thick layer of dead
The use of large tillage machinery can successfully eliminate RCG
if combined with a proper flooding regime. This method, however,
requires the use of large, expensive equipment, and requires the
ability to manipulate water levels. Additionally, use of tillage
to manage RCG assumes that you have no species or communities of
concern that you are trying to preserve at the site. If you are
working in a sensitive area or in a relatively intact native system,
this may not be a viable option. The purchase of the large tillage
equipment (48-inch tillage plates and tractor) can be prohibitively
expensive, but it may be available locally for rental or borrowing.
To eliminate large, dense RCG infestations using tillage + flooding,
you should till through the RCG sod layer as soon as it is possible
in the field season (usually, as soon as it is dry enough). The
initial tillage may require several passes of the equipment, since
the RCG sod layer may be thick and tough. Let the exposed stems
and rhizomes dry-out. You will need to till several times during
the fieldseason to break-up and dry all rhizome fragments (until
you have nothing left but broken-up clods of soil). Finally, when
the winter flooding begins, close floodgates and keep the entire
area inundated at least 18 inches deep through late spring (late
May-June) the following year. This combination of methods will eliminate
large infestations of RCG, but follow-up (i.e. spot herbicide treatment
with a backpack sprayer) will still be required for several years,
since some RCG plants will survive or will reinvade the site. Active
restoration will be necessary if a remnant seed bank does not exist.
Controlling the hydrology of the site to lengthen the time an area
spends totally submerged may be a viable control strategy if you
have control over the hydroperiod of your site.
Burning generally does not kill mature RCG, and similar to occasional
mowing, actually appears to stimulate additional stem production
unless the fire burns through the entire RCG sod layer down to the
mineral soil (which in turn, may create other problems). In most
cases, RCG remains green long into the season, and so does not burn
very hot. Herbicide treatment prior to burning can facilitate a
prescribed fire, especially outside of typical "fire seasons." Prescribed
fire can however, be used as a pretreatment to tillage, shade cloth,
or prior to herbicide application for good results, since the fire
will remove the aboveground dead litter and standing vegetation.
Burning for several years in a row is generally not possible because
of lack of fine fuels after the first-year burn.
Solarization (essentially baking under clear or black plastic)
or the use of a thick woven geotextile shade cloth can be used to
eliminate RCG. In dense areas of patchy RCG growth, this method
can provide specific, targeted control . In areas where RCG is mixed-in
with desirable species, the kill of those desirable species may
or may not be an option. Also, the use of certain materials for
this method depends on your overall management goals. Excellent
control of RCG can also be accomplished by using a thick woven plastic
fabric (Mirafi(r) or Amoco(r) brands), held in place by 7-inch gutter
spikes and washers and duck-bill tree anchors. The fabric is kept
in place for over one year (over an entire growing season), even
under inundation. This method will kill all plants under the cloth.
Revegetation or reseeding is generally necessary with this method.
Shade cloth is initially expensive (approximately $400 per 12 ft
x 350 ft roll), but can be reused several times, and this method
does not require follow-up visits during treatment. Mowing prior
to the installation of shade cloths greatly facilitates installation.
Small patches can likely be treated using black plastic bags, if
they are kept in place for the entire duration, the edges are tacked-down
firmly, and the bags do not shred.
Grazing may be effective means for controlling reed canarygrass
but the palatability of RCG is questionable--the genus Phalaris
is notoriously unpalatable and an illness associated with the
affects of consumption is called 'Phalaris staggers' (Marten et
al., 1976). Cattle prefer RCG when stems and leaves are young and
succulent, but do not prefer it once stems become old and tough.
Goats and sheep will graze on RCG. Grazing can be combined with
another treatment method (followed by tillage, herbicide, shade
cloth), for good control. Grazing can also be inappropriate in wetland
settings (Hutchison, 1992).
There are no known biological control agents for RCG.
RCG can be successfully controlled by the proper use of herbicide.
Small stands or clumps of RCG can be effectively killed with one
application, but large infestations will likely require applications
over several years to be effective. Since RCG frequently grows in
wet areas, only herbicides approved for aquatic habitats are allowed
in many situations. As with all herbicide use, be sure to read and
follow all label instructions and to abide by all state regulations.
Glyphosate (Rodeoï¿½, Aquamasterï¿½, or Glyproï¿½ among others) applied
in a 2% solution (1.08% active ingredient (a.i.)) with a nonionic
surfactant works well to kill RCG. Glyphosate (Rodeo) is a non-selective
herbicide that kills or injures nearly all plant species. Glyphosate
is also available in many other formulations (e.g. RoundUpï¿½). These
work well to kill RCG, but are not labeled for aquatic use, so be
aware of the areas where you plan on applying herbicide. Sethoxydim
(Vantageï¿½) is a grass-specific herbicide that has been used to kill
RCG with some success, but it is also not labeled for aquatic use.
Depending on the size and distribution of your infestation, the
herbicide can be foliar-applied using a dripless wick applicator,
backpack sprayer, or boom sprayer. Herbicide should be applied to
foliage during the growing season. Application can occur in mid-summer
(just prior to summertime dormancy) or preferably in late fall (just
prior to frost and wintertime dieback). It is recommended to apply
herbicide at these times, since it is speculated that these are
the times of year when RCG is most actively translocating carbohydrates
(along with the herbicide) down into the root system. You may also
combine an herbicide treatment with another control treatment for
good results. First, eliminate the aboveground dead litter by mowing
or burning, then allow the RCG stems and leaves to regrow to boot
height. This helps obtain better herbicide coverage and reduce total
herbicide use, since you are spraying only living green RCG that
is 12" tall vs. 6' tall stems mixed with old dead leaves. Follow-up
monitoring and treatment is necessary for several years to ensure
Planting fast-growing shrubs or trees may eventually eliminate
RCG since it is intolerant of year-round shade, but depending on
your management goals and objectives, this may not be a viable option.
The best management approach to use will depend on your overall
management goals and objectives, the size, distribution and location
of your RCG infestation(s), your capability and willingness to use
herbicides (or not), and your available resources (staff and volunteer
time, money, equipment, etc). The following recommendations are
not necessarily the best management methods for every situation,
nor are they presented in an order of preference. The methods listed
below have however, been used with some success. Also, every method
will require follow-up monitoring and treatment (including replanting
native species if necessary) to ensure the long-term success of
Scattered individual plants or small patches in healthy native
1. Dig out using a shovel
2. Spot-spray or wick with herbicide
3. Spot flame with a propane torch (only works for seedlings or
Distinct patches of RCG within a matrix of native vegetation
1. Dig out using a shovel (depends on size)
2. Cover with shade cloth (may be preceded by mowing)
3. Mow (to eliminate seeds), then spot-spray or wick with herbicide
4. Spot-spray or wick with herbicide
Large patches (up to several acres) of RCG with scattered native
(Which method you choose will depend on how much you want to
keep your native vegetation)
1. Mow then cover with shade cloth
2. Mow then herbicide (wick, spot-spray or boom)
3. Herbicide using appropriate application technique
4. Spot-burn then spot-spray regrowth
5. Cover with shade cloth (may be preceded by a mow treatment)
Large (hundreds of acres) monocultures of RCG
1. Mow using large mower, herbicide spray using boom sprayer
2. Prescribed burn, then herbicide spray using boom sprayer
3. Tillage and flooding
Summarized below are references to papers providing more detail.
Mandy Tu, Ph.D., works with the Invasive Species Intiative of The Nature
Conservancy, Oregon Chapter.
Her PowerPoint presentation chronicles the comparison of various control
efforts in Oregon. (5.4 MB) Download
For a quick look at the results of the study, here's a single PowerPoint
slide (53 KB): Download now.
The following is the now published paper discussing the study: Controlling
Phalaris in the PNW
Authored By: Mandy Tu, The Nature Conservancy's Wildland Invasive Species
The report by Galatowisch and Reinhart (UMn) on best management
practices for reed canary grass can now be downloaded/printed from the
U.S. Shorebird Conservation Plan website at:
DNR page on Reed Canary Grass
A study by the WDNR used Landsat satellite imagery to map wetlands where reed canary grass dominates the plant community in a pilot area covering a large portion of southern Wisconsin. The map documents 102,868 acres of reed canary grass dominated wetlands at a minimum mapping unit of 1/2 acre, or 14% of the wetlands in the pilot area. The map and the document describing its production are at http://dnr.wi.gov/org/water/fhp/wetlands/assessment.shtml. Go to "Assessing Wetland Biological Condition Over Large Areas."
version of this page (19 KB)
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