Hi, Linda,

Good eye to remove that plant -- it is classified as a noxious invasive weed in Vermont as it does displace some of our important native plants within our ecosystem.  Check out this link to VT Invasives to learn more about the plant and how to manage its removal.  Note that there are two Knotweeds -- Japanese and Giant, but their treatment will be very similar, so check out both entries to formulate a plan of removal.  This site from Penn State also has some great photos of many stages of growth so you might identify other patches at your new property.

Though many sources, including the VT Invasives and Penn State pages, suggest the use of glyphosate herbicide (roundup) to erradicate the plant, there are a lot of potential health concerns related to the continued use of this chemical compound.  Learn more from this U of Maryland site before deciding what may work for you.

Knotweed is edible during its early stage of growth, so you could experiment with that or feed the foliage to your chickens.  Otherwise, get rid of it, and commit some tenacity to the project so you can come out knotweed free on the other side.

Cheers!
Genica