(I may already have a #402121 We are having a major problem erradicating (getting rid of!) petasites japonicus. We have tried a variety of products but it just keeps spreading & that is scary! PLEASE HELP US!
Snyder County Pennsylvania
What products have you used? When did you apply those products.
Established perennials can be difficult to control as they build large energy reserves underground. If the foliage is damaged or killed, they are able to access the stored energy reserves and push up new growth.
Best time to control perennials is in the fall, especially with systemic herbicides.