Waterhemp and Palmer amaranth are both now listed on the Ohio noxious weed law, which means that landowners must take steps to control infestations and prevent further spread. Since these are annual weeds, preventing spread is achieved by preventing plants from reaching maturity and producing seed. This is the basis for our “No pigweed left behind” effort, for which the goal is to create an understanding that the only way to beat these weeds is to prevent seed. Prevention needs to occur in any area that might be subject to infestation, such as roadsides, parks, conservation seedings, parks, etc, in addition to agricultural fields. The entities managing these areas are responsible for recognizing and controlling infestations of waterhemp and Palmer amaranth, but this does not always occur. Not everyone involved in crop production or land management is aware of the waterhemp/Palmer problem to begin with, and many managers are busy enough that preventing noxious weed problems has low priority.
Our advice is to pay attention to what’s happening in your area or in the areas that you farm, with the goal of becoming aware of new infestations early enough that plant maturity and seed can still be prevented, regardless of where they may be occurring. We recommend as a first step contacting the land manager or owner to explain the issue, make them aware that they have an infestation, and request that action be taken. However, where it’s not possible to have this conversation, or there is a refusal to take action, the Ohio noxious weed law can be used to try to force action. A two-page summary of the noxious weed law that can be found here on the OSU Ag Law Blog, and also links directly to the law itself.
The basic idea here is that following an unsuccessful attempt to work with a landowner or manager, noxious weed issues should be reported to township trustees, and this must be done in writing. The trustees then have the responsibility to deal with the issue, and the method for doing so varies depending upon what the land is used for and who is managing it. If it’s necessary to use the noxious weed law, be sure to start the process early enough in summer, well before potential seed production. There is a need to allow time for all of the steps in the process to occur, and for notifications to be received and acted on (or not). Our experience is that not all landowners and managers will take action upon first notification, and in addition to action, their response to notification can include minimal response of protesting their need to act. Waiting too late to start the process can result in lack of resolution of these issues in time to prevent plant maturity and seed production. The noxious weed law has been used several times within the last two years to force managers to control Palmer amaranth, and could be used to accomplish the same for waterhemp, which was recently added to the list. Consider the law a tool to prevent the establishment and spread of these weeds when other methods are ineffective.