Do you have Japanese Knotweed in your garden?


This is the ideal time of the year to check if you have Japanese Knotweed on your land.

The above photo is of newly emerging shoots of Japanese Knotweed – this is what you should be looking out for if you suspect you have it growing on your land. It’s really easy to recognise at this time of year because the stems (not unlike an asparagus spear) are so vibrantly red and obvious as they burst out of the ground – usually before anything else has put out new leaves.

Although it is a very invasive plant, you don’t need to panic and you certainly shouldn’t attempt to dig it up! That’s possibly one of the worst methods of dealing with Japanese Knotweed because you’re pretty much guaranteed to make the situation worse, not better.

Because of the way Japanese Knotweed spreads, any attempt to dig it up, strim it, mow it or even walking over it can cause the plant to react by putting out lots of new shoots. And it does this rapidly – what was once a small manageable patch can quickly become a very large problem.

It is possible to weaken the plant by spraying it with weedkiller, however this method has quite a lot of drawbacks:

  • Most importantly – note that I said it would only weaken the plant. Spraying Japanese Knotweed with even a professional strength weedkiller will not kill the plant outright. There will need to be repeated applications over many seasons to try to get it under control – this proves to be costly, both financially and environmentally (see the final point).
  • It seems to be an unwritten rule that shortly after spraying weedkiller, the weather turns to rain! Not only is this annoying but it washes most of the product off the leaves making it an ineffective and costly treatment.
  • If Japanese Knotweed appears in a bed or border, spraying weedkiller in those areas is impossible to do without killing other plants. (Weedkiller kills ALL plants, it doesn’t discriminate between good and bad).
  • There is a mounting body of evidence to suggest that spraying the sort of weedkiller necessary for tackling Japanese Knotweed has a negative impact on beneficial insects such as bees, hoverflies and butterflies.

Tree Heritage use a different method to kill Japanese Knotweed which doesn’t pose a threat to other plants or wildlife. We have successfully treated a number of outbreaks in peoples gardens and to date, there have been no new shoots emerge.

If you do see it, remember where it is, take photos if necessary (especially if you’ve got a large garden/school/estate) and then get in touch with us: Talk to us

For more information, have a look at our Japanese Knotweed pages:

Japanese Knotweed Treatment

Japanese Knotweed Identification

One final photograph you can use to identify it in your garden: