Invasive Plant Control Database

Welcome to the Invasive Plant Control Database

This website contains information on how to control many invasive plants common to the Midwestern United States. Information was collected from both scientific literature and expert opinions and summarized by the Midwest Invasive Plant Network (MIPN), in partnership with the Mark Renz lab from the University of Wisconsin-Madison. Methods that are uncommon, do not provide sufficient control, or lack information for determining effectiveness on target species are omitted. For each species, information was reviewed by four individuals, including two identified as experts on control of that species. Information is searchable by several fields to improve the user’s ability to find pertinent information. To view the search feature, you must first select an invasive plant. Additionally, users have the option of entering personal experiences with managing specific species (see “add new case studies” under search results). These case studies will be visible to all users once verified by MIPN staff.

We make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability, or availability with respect to the information or products on the website. Any reliance you place on such information is therefore strictly at your own risk. References to pesticide products on this website are for your convenience and are not an endorsement or guarantee of one product over another.

Step 1: Select Plant

Step 1: Select a species by choosing a common or scientific name from the list, or by typing a name in the search box.

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Step 2: Select Search Parameters

Step 2: Select search parameter(s) of interest. If no parameters are selected all control methods will be displayed. For effectiveness ratings, methods that meet or exceed the criteria selected will be displayed.

Under the Search Results you will find

  • Plant Identification information – information on species identification, including photographs and a current distribution map.
  • Ecological Threats – threats posed to natural ecosystems by this species.
  • Case Studies – Detailed success (and failures) on how to control specific species contributed by experienced personnel.
  • Non-chemical and chemical control methods that fit the selected search criteria. Please note you are responsible for using pesticides in accordance with the label directions and state and federal laws. Herbicide availability and registered uses vary from state to state. Contact your state department of agriculture for information on the correct use and licensing required for any pesticide application.

You may reset the search criteria or the species you have selected at any time by selecting the corresponding links on the right hand side of the page.

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Effectiveness (year after treatment): 
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Search Results

Polygonum cuspidatum (Japanese knotweed)

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Non-Chemical controls
New (Type)Description
Type -
Mowing

User Type -
Novice

Effectiveness -
in season
year after treatment
Mow or cut at least 4 times a year. Mow or cut whenever knotweed reaches 2-3' in height and repeat through the fall. Newly established populations can be controlled after 3 years, but established populations will only be suppressed. Use a mower that bags cut material or rake and bag cut material after mowing and dispose of it in a landfill or burn it to avoid potential for above-ground tissue to resprout.
Type -
Prescribed burning

User Type -
Professional

Effectiveness -
in season
year after treatment
Spring burns can kill germinating seedlings and suppress above-ground growth of established plants depending on fire intensity. After the fire, established plants will quickly resprout and reinvade areas; this management method is not recommended unless integrated with other techniques. Fire may benefit other species well-adapted to this management (e.g., prairie grasses), resulting in improved competition with knotweed. A hand-held propane torch can be effective for treating seedlings.
Type -
Removal

User Type -
Novice

Effectiveness -
in season
year after treatment
Pull at least 4 times a year. Rhizomes of newly established populations can be removed by digging, but care must be taken to remove all rhizomes and perennial roots as very small amounts (0.25 oz) can resprout. This is not recommended for established populations because of the depth (6' taproot) and width (65' rhizomes) of the root system. Bag all cut or pulled material and dispose of it in a landfill or burn to avoid potential for root material or above-ground tissue to reroot.
Type -
Grazing

User Type -
Novice

Effectiveness -
in season
year after treatment
Grazing may reduce shoot densities and height but will not eradicate populations. Cattle, sheep, horses, donkeys, and goats will feed on Japanese knotweed. Animals prefer the young shoots as they emerge in the spring, but preference declines as stems become woody in summer. If possible, remove last season's stems before grazing as these can deter animals. Although grazing can help reduce the spread into uninfested areas, it has not been found to eliminate populations. Grazing will stimulate the rhizomes to resprout throughout the season, thus repeated grazing will be required throughout the growing season to effectively suppress populations.
Type -
Manipulation of the environment

User Type -
Professional

Effectiveness -
in season
year after treatment
Mulching or covering with a tarp can slow the spread of knotweed. Tarp must have some slack in it or the plant will stretch and break the tarp. Watch for new sprouts beyond the edge of the mulch or tarp as knotweed sprouts readily from the rhizome. Populations will need to be covered for at least two years to suppress plants, but this technique will rarely eradicate populations.
Chemical controls
New (Type)IngredientsDirections
Type -
Pre-emergence

User Type -
Professional

Effectiveness -
in season
year after treatment
Active Ingredient (A.I.):
tebuthiuron

Common product name:
Spike 20P; Tebuthiuron 20 P
Rate -
(broadcast) 2.5 - 3.6 lb/A (2 - 3 lb a.i./A)
(spot) 0.009 lb/sq ft (0.006 lb a.i./sq ft)

Timing -
Apply during late winter or early spring when soil is not frozen. Apply to ground infested with target species in bands 4-10' wide spaced 4- 0' apart. Width and spacing will depend on the area and species to be treated.

Remarks -
Tebuthiuron is also available as a liquid formulation, Spike 80DF. This formulation is applied in a banded spray or as a spot treatment

Caution -
Do not apply directly to water or to areas where surface water is present. Applications can result in bare ground as tebuthiuron is not selective and can remain in the soil for several years depending on application rate. Use of this chemical in areas where soils are permeable, particularly where the water table is shallow, may result in groundwater contamination. In areas fitting this description Spike can be used at rates as low as 2.5 lb/A (0.5 lb a.i./A), but partial control should be expected. Any plant with a root system that intercepts the area treated with this herbicide can be damaged or killed. Do not apply more than 20 lb/A (4 lb a.i./A) a year. Do not apply this product more than once a year.
Type -
Foliar

User Type -
Professional

Effectiveness -
in season
year after treatment
Active Ingredient (A.I.):
imazapyr

Common product name:
Arsenal; Stalker (Aquatic: Habitat; Imazapyr 2sl)
Rate -
(broadcast) 48 - 64 fl oz/A (0.75 - 1 a.e./A)
(spot) 0.5 - 1% (0.01 - 0.02 lb a.e./gal)

Timing -
For best results cut twice (in spring when it reaches 3', then again when plant flowers), then spray fall regrowth when it reaches 3'.

Caution -
Use product labeled for aquatic use if potential exists for solution to contact surface waters. Applications can result in bare ground as imazapyr is not selective and can remain in the soil for several months to over a year depending on application rate. Overspray or drift to desirable plants should be avoided, as even minute quantities of the spray may cause severe injury to plants.
Type -
Foliar

User Type -
Novice

Effectiveness -
in season
year after treatment
Active Ingredient (A.I.):
2,4-D

Common product name:
Many (Aquatic: DMA 4 IVM; 2,4-D Amine 4)
Rate -
(broadcast) 2 - 2.5 lb a.e./A
(spot) 4% (0.11 lb a.e./gal)

Timing -
For best results cut twice (in spring when it reaches 3', then again when plant flowers), then spray fall regrowth when it reaches 3'.

Remarks -
Spring or summer applications of this herbicide are not effective in controlling this plant and this herbicide should only be applied in the fall to regrowth.

Caution -
Use aquatically labeled product if potential exists for solution to contact surface water. Use of this chemical in areas where soils are permeable, particularly where the water table is shallow, may result in groundwater contamination. Overspray or drift to desirable plants should be avoided, as even minute quantities of the spray may cause severe injury to plants.
Type -
Foliar

User Type -
Novice

Effectiveness -
in season
year after treatment
Active Ingredient (A.I.):
triclopyr

Common product name:
Garlon 4; Element 4 (Aquatic: Garlon 3A; Element 3A)
Rate -
(broadcast) 64 - 128 fl oz/A (2 - 4 lb a.e./A)
(spot) 1.5 - 2.25% (0.06 - 0.09 lb a.e./gal)

Timing -
For best results cut twice (in spring when it reaches 3', then again when plant flowers), then spray fall regrowth when it reaches 3'.

Remarks -
Spring or summer application of this herbicide are not effective in controlling this plant and applications should only be made in the fall.

Caution -
Use product labeled for aquatic use if potential exists for solution to contact surface waters. Use of this chemical in areas where soils are permeable, particularly where the water table is shallow, may result in groundwater contamination. Overspray or drift to desirable plants should be avoided as even minute quantities of the spray may cause severe injury to plants.
Type -
Foliar

User Type -
Professional

Effectiveness -
in season
year after treatment
Active Ingredient (A.I.):
aminopyralid

Common product name:
Milestone
Rate -
(broadcast) 7 - 14 fl oz/A (0.08 - 0.11 lb a.e./A)
(spot) Equivalent to broadcast rates.

Timing -
For best results cut twice (in spring when it reaches 3', then again when plant flowers), then spray fall regrowth when it reaches 3'.

Remarks -
14 fl oz/A can be used as long as less than half of the area is treated. Depending on the volume of solution applied per acre, typical mixtures for spot treatments are 8-16 mL Milestone per gallon of water.

Caution -
Do not apply directly to water or to areas where surface water is present. Remains in soil for up to one year depending on application rate. Overspray or drift to desirable plants should be avoided, as even minute quantities of the spray may cause severe injury to plants. Do not compost treated plants as herbicide can persist through composting process.
Type -
Foliar

User Type -
Novice

Effectiveness -
in season
year after treatment
Active Ingredient (A.I.):
glyphosate

Common product name:
Roundup Pro; many others (Aquatic: Rodeo; AquaNeat)
Rate -
(broadcast) 3 - 8 lb a.e./A
(spot) For a 3 lb a.e./gal product. 4 - 8% (0.12 - 0.24 lb a.e./gal)

Timing -
For best results cut twice (in spring when it reaches 3', then again when plant flowers), then spray fall regrowth when it reaches 3'. Cut again 30 days after spraying for increased effectiveness.

Caution -
Use product labeled for aquatic use if potential exists for solution to contact surface waters. Applications can result in bare ground as glyphosate is not selective. Overspray or drift to desirable plants should be avoided, as even minute quantities of the spray may cause severe injury to plants.
Type -
Cut stump

User Type -
Novice

Effectiveness -
in season
year after treatment
Active Ingredient (A.I.):
triclopyr

Common product name:
Garlon 4; Element 4 (Aquatic: Garlon 3A; Element 3A)
Rate -
(spot) 20 - 25% in oil (0.8 - 1 lb a.e./ gal)

Timing -
Apply any time of year when plant is actively growing, although spring applications will likely require retreatment. Wait for 3' of regrowth before retreating.

Remarks -
Applications can also be injected directly into the stem. Inject 1mL of a 50% (0.0004 lb a.e.) solution or 0.5mL (0.0004 lb a.e.) of an undiluted solution between ground and the top of the second basal joint (node) from the ground. Products containing this active ingredient can have different instructions for mixing. Labels will recommend mixing the product in a water or oil based carrier (e.g. basal bark oil). Consult the label to determine the appropriate carrier.

Caution -
Use product labeled for aquatic use if potential exists for solution to contact surface waters. Use of this chemical in areas where soils are permeable, particularly where the water table is shallow, may result in groundwater contamination. Overspray or drift to desirable plants should be avoided as even minute quantities of the spray may cause severe injury to plants.
Type -
Cut stump

User Type -
Novice

Effectiveness -
in season
year after treatment
Active Ingredient (A.I.):
triclopyr + 2,4-D

Common product name:
Crossbow; Chaser
Rate -
(spot) 4% in oil (triclopyr: 0.04 lb a.e./gal + 2,4-D: 0.08 lb a.e./gal)

Timing -
Apply any time of year when plant is actively growing, although spring applications will likely require retreatment. Wait for 3' of regrowth before retreating.

Caution -
Do not apply directly to water or to areas where surface water is present. Use of this chemical in areas where soils are permeable, particularly where the water table is shallow, may result in groundwater contamination. Overspray or drift to desirable plants should be avoided, as even minute quantities of the spray may cause severe injury to plants.
Type -
Cut stump

User Type -
Novice

Effectiveness -
in season
year after treatment
Active Ingredient (A.I.):
glyphosate

Common product name:
Roundup Pro; many others (Aquatic: Rodeo; AquaNeat)
Rate -
(spot) For a 3 lb a.e./gal product. 20 - 25% (0.6 - 0.75 lb a.e./gal)

Timing -
Apply any time of year when plant is actively growing, although spring applications will likely require retreatment. Wait for 3' of regrowth before retreating.

Remarks -
Applications can also be injected directly into the stem. Inject 2-5mL (0.002-0.005 lb a.e.) between ground and the top of the second basal joint (node) from the ground.

Caution -
Use product labeled for aquatic use if potential exists for solution to contact surface waters. Applications can result in bare ground as glyphosate is not selective. Overspray or drift to desirable plants should be avoided, as even minute quantities of the spray may cause severe injury to plants.