A Landowner's Guide for the Control of Phragmites
The Mighty
Phragmites
Its proper name - Phragmites - makes it sound like a crawling
creature, or a disease. But phragmites, also known as common reed, is a large,
coarse, perennial grass often found in wetlands. Although scattered clumps of
phragmites provides cover for small mammals and birds, it usually forms large,
dense stands that provide little value for wildlife. Phragmites reduces the
diversity of plant and wildlife species.
Phragmites is found in wetlands
worldwide. It grows in wet areas including fresh or brackish marshes, creeks,
edges of ponds and lakes, ditches, and the dune systems of barrier coastal
islands. Dense stands of phragmites usually are associated with areas where soil
has been exposed or disturbed. The plants are less competitive when water levels
vary by seasons and years. The exact abundance and current rate of spread of
phragmites in Maryland is unknown. However, it is increasing in abundance and
distribution.
Phragmites has a thick stalk that
can reach 13 feet in height. It has a large plume-like flower that persists
throughout the winter. Phragmites most often spreads by creeping rhizomes
(roots). All stands have vertical and horizontal rhizomes, and young stands have
long surface runners that help in rapid expansion of the colony.
Controlling Phragmites
Techniques used to control phragmites may include chemical treatment (i.e.,
spraying herbicides) or physical treatments such as mowing and flooding.
Multiple treatments are usually necessary to effectively control a heavy stand.
Controlling phragmites in wetlands by any method may require advance approval by
state and federal agencies before treating. Based upon experience obtained in
Maryland and other states, the most practical method of controlling phragmites
is treating the plants with glyphosate or imaszapyr herbicides approved for
aquatic use.
Chemical Control
Glyphosate (the formulation approved by the U.S. Environmental Protection Agency
for use in wetlands is sold under trade names such as Rodeo, Aquaneat, and
Aquastar) is a broad spectrum aquatic herbicide that is virtually nontoxic to
mammals, birds, and fish when used according to instructions. It can be
purchased at any store that sells agricultural chemicals. Imazapyr is the active
ingredient utilized in the formulation of Habitat which is also a broad spectrum
herbicide effective in controlling Phragmites. All herbicides must include a
non-ionic surfactant which allows the herbicides to adhere to the plants leaves,
stalks and rhizomes for effective control. Surfactants must be acquired
separately and added to tank mixtures, unless otherwise noted on label
recommendations obtained with the herbicides.
When applied to the foliage of
actively growing plants, both imazapyrs and glyphosates are rapidly absorbed and
transported throughout the plant tissues. The herbicides kill the entire plant:
leaves, stems, and rhizomes. This is especially important in the control of
phragmites since it spreads through rhizomes. It may be applied in or around
wetlands using aerial spray equipment, a boom or handgun from a boat, or from
the shore using spray equipment. However, large stands in open areas are best
treated with an aerial application by helicopter. Phragmites can be treated
successfully when plants are actively growing and are at mid- to full-bloom
(late July through October but before a killing frost).
Treatment before or after this
stage of growth may result in reduced control. Herbicides should be applied at a
rate of 4-6 pints per acre where equipment used has been calibrated to achieve
accurate volume (gallons) to the acre. Equipment (backpacks/handheld) sprayers
should follow the recommended percentage of concentrated herbicide per gallon of
total mixture found on the products label. Be sure to follow the dilution and
surfactant rates prescribed on the product label for maximum effectiveness. The
use of a surfactant ensures that the herbicide is absorbed by the plant stems
and leaves. Enough herbicide should be applied to wet the plant but avoid
runoff. Spray coverage should be uniform and complete. Phragmites will die
within 6-8 weeks and should then be burned or mowed where safely done so. Dead
phragmites cane should be left on site to prevent spread by seed during removal
to adjoining areas. In heavily infested areas some regrowth may occur from
unconnected rhizomes. In addition, seedling growth may occur. For best results,
the some area should be sprayed in two successive years, then spot-treated in
succeeding years to prevent reestablishment.
Important: A toxic
chemicals application permit is needed to spray phragmites with aquatic
herbicide in wetlands. To obtain a permit application, please contact: Maryland
Department of the Environment's Industrial Discharge Permits Division
410-537-3323 or visit website;
http://www.mde.state.md.us/assets/document/permit/MDE-WMA-PER015.pdf
Physical Control
Physical control is an alternative only if conditions allow. This will help to
remove the litter of matted canes and allows light to reach the soil. This
increased light will encourage germination of seeds from desirable plants.
Mowing often (6-8 times during the growing season) where feasible is the most
widely used method of stressing phragmites and encouraging native plants.
Important: Prior to burning you should contact the Maryland Department of
Natural Resources Forest Service office (410-260-8531) in your county to obtain
a burning permit and for information regarding safe burning practices. If you
plan to disturb wetlands through filling, excavating or vegetation removal, you
should consult the Maryland Department of the Environment's Water Management
Administration website;
http://www.mde.state.md.us/Permits/WaterManagementPermits/index.asp #3.05,
or call (410-537-3000) – (Nontidal/Tidal) to determine if a wetlands permit is
required.
The Future
The conservation of our natural resources concerns everyone. Many people rely on
wetlands resources for their livelihood, recreation or the enjoyment of seeing
and experiencing nature. Maryland has lost nearly 45 percent of its wetlands.
The aggressive invasion of phragmites into Chesapeake Bay wetlands is
contributing to further loss and degradation of our remaining wetland habitats.
If you are interested in halting
the invasion of this plant and would like to discuss techniques applicable to
your property, available assistance programs, or obtain a list of licensed
applicators or wetland restoration professionals that specialize in the control
of phragmites, please contact:
Waterfowl Habitat Specialist – Donald Webster
MD DNR – Wildlife and Heritage Service
828B Airpax Road, Suite 500
Cambridge MD 21613
410-221-8838(ext.103)
Demonstration Area
Would you like to see the beneficial effects of eliminating phragmites from your
wetlands? Visit the Chesapeake Bay Environmental Center (C.B.E.C.) near
Grasonville, Maryland and enjoy a self-guided tour of Lake Knapp, a 12-acre lake
that was once dominated by phragmites. Following a combination of aquatic
herbicide application and burning to control phragmites, the lake has been
restored to a wetland teeming with waterfowl and wading birds. Groups are
welcome to make reservations for a guided tour of the demonstration project and
other wildlife viewing exhibits by calling 410-827-6694.
Directions:
From Baltimore and Washington D.C., take U.S. Route 50 East to Maryland's
Eastern Shore. Continue on Route 50 and take Exit 43 B, and follow the C.B.E.C.
signs. From Route 50 West, use Exit 45B, and follow signs.
Author: Larry J.
Hindman, Waterfowl Project Manager
Wildlife and Heritage Service
Maryland Department of Natural Resources
828B Airpax Road, Suite 500
Cambridge MD 21613
410-221-8838
Acknowledgements: This information was
made possible by a U.S. Fish and Wildlife Service Challenge Grant and
contributions from the Monsanto Company, Chesapeake Wildlife Heritage, Wildfowl
Trust of North America, Inc., and Maryland Department of Natural Resources
Wildlife and Heritage Service.
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