Property Owners
If you think you have Japanese Knotweed on your property, do not dig up the plant, as knotweed can spread roots several feet deep and over 10 feet across - and tiny root fragments can start new plants (there is no safe way to dispose the roots). Herbicide can eradicate knotweed if performed optimally. It is best to not cut down the knotweed so large canes can be injected with glyphosate, a very effective treatment. If you do cut down knotweed canes, do so prior to June, so there is enough regrowth to allow spraying, and make sure the canes are thoroughly dried out in the sun before discarding them.
Herbicide treatment should only be done after the knotweed starts to flower, when it is taking nutrients (and herbicide) to the root system, and before the first hard frost (August through early October in the Adirondacks). Do not cut the knotweed for at least 3 weeks after treatment to allow time for the herbicide to get to the root system. In New York, property owners are permitted to apply non-restricted herbicide on their own property. If you treat knotweed on your own property and do not have an injection gun, consider cutting the knotweed prior to June, then spray the leaves with 5% glyphosate (e.g. diluted Accord XRT II) in August or September.
If your property is in the Adirondack Park consider having Regional Inlet Invasive Plant Program (RIIPP) help eradicate the knotweed. Check out the RIIPP sheet, and slide show. There is no cost to property owner with treatments supported by donations to RIIPP, through the Saranac Lake Rotary Foundation - RIIPP fund.
The first step is to contact the Invasive Plant Coordinator (IPC) for your area. Current and former RIIPP IPCs are listed below. Check with Doug Johnson to learn how you could become a volunteer coordinator for your town.
RIIPP IPC Prior RIIPP IPC
Blue Mountain Lake Ellen Collins
Bolton Landing Ann Green
Chestertown Jan McCann
Garnet Lake Bob Manning and Roy Keats
Indian Lake Terry DeArmas
Inlet/Eagle Bay/Big Moose Bonnie Lutz
Lake Piseco Katy Weil
Lake Placid Larry Master
Long Lake Chuck Taylor
Lower Hamilton County Caitlin Stewart
(Benson/Hope/Lake Pleasant/Morehouse/Speculator/Wells)
Minerva Mike Corey
North Creek/North River Evelyn Greene
Old Forge
Saranac Lake Adrien Vlach
Tupper Lake Scott Chartier
Warrensburg
If there is no volunteer coordinator for your town/area or you could assist the current coordinator or want to learn more, contact Douglas Johnson.
You will need sign an Adirondack Research Indemnity Agreement and sign the lawn contract with the pesticide applicator after reviewing the pesticide label. Contracts can be signed electronically.
The signed forms should be given/sent to your IPC. Then arrange to have the IPC review where the knotweed is on your property. The IPC will coordinate with the pesticide applicator to hopefully treat the knotweed in August or September. There is no guarantee that the property will be treated.
The first treatment usually kills over 90% of the knotweed, and a second treatment (the next year) usually kills over 98%, with a third, fourth, and fifth year treatment sometimes needed. The knotweed will start to look sick about a week after treatment. You should not cut down knotweed for at least three weeks after it is treated so the pesticide will be taken down to the root system. It is best to leave the knotweed in place after treatment, in which case a second treatment can be done about four weeks later to plants that were missed.
Herbicide treatment should only be done after the knotweed starts to flower, when it is taking nutrients (and herbicide) to the root system, and before the first hard frost (August through early October in the Adirondacks). Do not cut the knotweed for at least 3 weeks after treatment to allow time for the herbicide to get to the root system. In New York, property owners are permitted to apply non-restricted herbicide on their own property. If you treat knotweed on your own property and do not have an injection gun, consider cutting the knotweed prior to June, then spray the leaves with 5% glyphosate (e.g. diluted Accord XRT II) in August or September.
If your property is in the Adirondack Park consider having Regional Inlet Invasive Plant Program (RIIPP) help eradicate the knotweed. Check out the RIIPP sheet, and slide show. There is no cost to property owner with treatments supported by donations to RIIPP, through the Saranac Lake Rotary Foundation - RIIPP fund.
The first step is to contact the Invasive Plant Coordinator (IPC) for your area. Current and former RIIPP IPCs are listed below. Check with Doug Johnson to learn how you could become a volunteer coordinator for your town.
RIIPP IPC Prior RIIPP IPC
Blue Mountain Lake Ellen Collins
Bolton Landing Ann Green
Chestertown Jan McCann
Garnet Lake Bob Manning and Roy Keats
Indian Lake Terry DeArmas
Inlet/Eagle Bay/Big Moose Bonnie Lutz
Lake Piseco Katy Weil
Lake Placid Larry Master
Long Lake Chuck Taylor
Lower Hamilton County Caitlin Stewart
(Benson/Hope/Lake Pleasant/Morehouse/Speculator/Wells)
Minerva Mike Corey
North Creek/North River Evelyn Greene
Old Forge
Saranac Lake Adrien Vlach
Tupper Lake Scott Chartier
Warrensburg
If there is no volunteer coordinator for your town/area or you could assist the current coordinator or want to learn more, contact Douglas Johnson.
You will need sign an Adirondack Research Indemnity Agreement and sign the lawn contract with the pesticide applicator after reviewing the pesticide label. Contracts can be signed electronically.
The signed forms should be given/sent to your IPC. Then arrange to have the IPC review where the knotweed is on your property. The IPC will coordinate with the pesticide applicator to hopefully treat the knotweed in August or September. There is no guarantee that the property will be treated.
The first treatment usually kills over 90% of the knotweed, and a second treatment (the next year) usually kills over 98%, with a third, fourth, and fifth year treatment sometimes needed. The knotweed will start to look sick about a week after treatment. You should not cut down knotweed for at least three weeks after it is treated so the pesticide will be taken down to the root system. It is best to leave the knotweed in place after treatment, in which case a second treatment can be done about four weeks later to plants that were missed.