Can Japanese Knotweed Come Back?

Like an unwanted house guest, Japanese knotweed can be difficult to get rid of. Patience and persistence are key to getting the job done properly.

Photo by Leonora Enking (View Original)

As we discussed in our blog about Japanese knotweed's growing cycle, this invasive species may appear to die off completely during the winter months. But appearances can be deceptive.

In reality, the plant tends to stay alive throughout the winter - it just goes into hibernation, like a hedgehog. During this dormant period, there may be no sign of the plant whatsoever above ground, but its hardy rhizome root system remains alive and well beneath the soil. Rest assured: it will return when spring arrives and the weather warms up!

But Japanese knotweed's apparent ability to rise from the dead isn't merely seasonal.

Can Japanese knotweed come back after it's been sprayed with herbicide?

Yes it can. As any Japanese knotweed expert will tell you, one application of herbicide is rarely enough to kill Japanese knotweed and ensure that it will never grow back.

Instead, it's wise to carry out multiple applications of herbicide (ideally between May and September, before the plant enters the dormant stage of its growing cycle).

As we mentioned at the start of this blog post, persistence is crucial when you're trying to get rid of Japanese knotweed for good. To eradicate the plant entirely, your Japanese knotweed contractor will need to visit your property several times - one dose of weedkiller just won't cut it!

If you're in a hurry, you might be better off forgetting about herbicides entirely and calling in the diggers instead. Excavation is a more expensive option, but it can be preferable when time is of the essence.

View our Japanese knotweed treatment plans for more information on how you can get rid of your Japanese knotweed once and for all.

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