There are some cases where it is not clear where a Japanese knotweed infestation has originated from. Shared gardens or land with ill-defined borders can lead to disputes between neighbours as both parties attempt to shift responsibility for removing the Japanese knotweed. In these instances, mediation is often required to reach an understanding between both parties and move forward with a treatment plan that is suitable for both. Many specialist treatment firms will consider discounts for a multi-property treatment plan if neighbours all work and pay together.