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Can you remove Japanese knotweed in Indiana in November?

Sources (1)

Indiana source only. Checked October 27, 2026. Not legal advice; follow the herbicide label.

Late in the cycle.Indiana DNR’s plan is: cut in late spring or early summer, treat the leaves in August, and herbicide works better in fall while the leaves send food to the rhizomes. If your knotweed leaves are already gone, start that cycle next spring.

When Indiana’s guidance says to do it

Cut in late spring or early summer, then treat the leaves in August; herbicide works better in fall when the leaves are sending food down to the rhizomes.

Source: Indiana DNR / IPSAWG invasive plant fact sheet – Japanese Knotweed

How to remove Japanese knotweed (Reynoutria japonica)

It's on Indiana's invasive plant rule (312 IAC 18-3-25), so we recommend removing it. Digging out the rhizomes is very hard work and tends to spread rhizome pieces, so it isn't recommended. Cutting alone (at least three cuts a season) only offsets new growth and won't get rid of it. Glyphosate or triclopyr on the leaves works, best after a first cut, following the label. Any rhizomes left in the soil will regrow once you stop.

Source: Indiana DNR / IPSAWG invasive plant fact sheet – Japanese Knotweed

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