Japanese knotweed in Ohio: is it illegal, and do you have to remove it?

Short answer: Japanese knotweed is on two Ohio lists. It can’t be sold or propagated, and because it is a prohibited noxious weed, a township can order an owner to cut or destroy it.

Get What’s OK to Plant ($12) Native plants matched to your Ohio ZIP, with nothing from the state invasive list. Or check your ZIP free.

What Ohio law says

Ohio’s invasive plant rule, OAC 901:5-30-01, lists Japanese knotweed (Fallopia japonica). The rule says no person shall sell, offer for sale, propagate, distribute, import or intentionally cause the dissemination of a listed plant in Ohio. It allows you to dispose of and control the plant as long as you don’t spread it. The rule does not contain a requirement to remove plants already growing on your property. The Ohio Department of Agriculture’s list took effect January 7, 2018 (OIPC summary).

It is also on Ohio’s prohibited noxious weed list as Reynoutria japonica (OAC 901:5-37-01, item R). Under Ohio Rev. Code 5579.05, when township trustees receive written information that noxious weeds are growing on land in the township, they notify the owner or person in charge, who has five days to cut or destroy them or show why there is no need to. Kudzu is on the same noxious weed list.

How to identify it

OSU’s weed lab (ID page) and the OIPC fact sheet describe: hollow, reddish-brown, bamboo-like stems with swollen nodes; alternate egg-shaped leaves about 4–6 inches long with a pointed tip; small greenish-white flower plumes in late summer. It can grow over 10 feet tall.

How to remove it

OIPC: large colonies are extremely hard to dig because of dense rhizomes; small patches can be dug if every piece goes into plastic bags for disposal. Repeated cutting or mowing within a growing season has worked, and systemic herbicide on regrowth controls it, usually over several applications. It spreads in fill dirt, so don’t move soil from a patch.

What to plant instead

Native shrubs we list for Ohio: buttonbush, American elderberry and silky dogwood. See native swaps and the official listing details.

Common questions

Is Japanese knotweed illegal in Ohio?

Yes. It is on Ohio’s invasive plant list (no selling, propagating or distributing) and on the prohibited noxious weed list (OAC 901:5-37-01).

Do I have to remove Japanese knotweed in Ohio?

Not automatically. But it is a prohibited noxious weed, and under ORC 5579.05 township trustees who receive written information about it notify the owner, who then has five days to cut or destroy it or show why that is not needed.

More Ohio guides

Tree of heaven in OhioHoneysuckle in OhioAll Ohio invasive plants