Fighting the Japanese Knotweed Invasion at Beach House

If you’ve stayed at Beach House for a self-catering break you’ll probably have appreciated that it’s actually a family holiday home. We decided to let others come and enjoy the views and other delights Mull has to offer as, unfortunately, we can’t use it all of the time.

We have wonderful grounds immediately surrounding the house, with our own forest, burn and gardens. Problem is, a few years ago we got an unwelcome visitor, better known to gardeners as Japanese Knotweed. It’s anyone’s guess how it got there, but the current thinking is that some bird probably brought it in as a seed from another part of the island.

The problem with this plant is its incredible rate of growth and ability to spread through the ground rapidly. It now covers a significant corner of the garden, so we popped up this month to attack it. We’re using a treatment from Roundup called Tree Stump & Root Killer, with a big badge on it saying it kills Japanese Knotweed too. Lets hope so!

Anyway, you can see what we’re dealing with in the video above.

Twitter: mullescape

3 thoughts on “Fighting the Japanese Knotweed Invasion at Beach House”

  1. Hi,

    Good to see that you are taking action against the Japanese Knotweed, but rather than spraying, have you considered using stem injection?

    This method has far more success than foliar application, is specific to the plant and has less impact on the environment. Our sister company Japanese Knotweed Control has been using it for 7 years in the UK including the highlands and islands with great success. Have a look at our web site and see what you think. If you want any more information, please let me know.


  2. Hi David

    Thanks for the advice. I’m pretty sure I did look at your site but there are a few reasons we opted for the spray tactic at this stage.

    1. The coverage of the knotweed is really large. As we lacked the time to methodically chop each shoot and inject it (and there are a huge number), we decided to get into the forest canopy it had developed and spray the leaves both top and bottom, whilst it was still actively growing and thus most likely to take the weedkiller into the plant proper.

    2. Cost – whilst I suspect an injection approach more directly gets the active ingredients into the roots of the knotweed, the cost of the equipment required to do this is considerably higher than using a 5L spray cannister from B&Q and diluting the active ingredents into water.

    So, had we both the time to spare, the money for pricey specialist equipment, and the patience, I think your approach would be the ideal.

    But we also recognise that this is a long haul job. I suspect we’ll be back in there again as soon as the surviving knotweed shows new signs of growth. And we’ll keep up this regime until it has been considerably depleted in its coverage.

    Eventually, when we’ve killed it back enough using the cheaper and quicker spraying method (though I’m sure not as effective), we’ll then be more likely to go in with the chop the stem and inject the plant approach.

    Of course, you can also do this using large cutters, a screwdriver and a pippette to spike into each stem.

    In an ideal world, of course, we’d find affordable and available garden experts to come and do it for us. But that’s not an option open to us on the beautiful, though slightly remote, Isle of Mull.


    Twitter: mullescape

  3. Hopefully the spraying we did earlier this year is having the desired effect, but we'll need to pop back up to Mull to dose it again as soon as new growth appears.A quick update on the knotweed issue. Obviously each winter the stems of the Knotweed drop their leaves but recent photos of the plant seem to show the whole thing looking a bit decimated after our concerted efforts to kill it.

    Hopefully that’s a good sign that we caught the knotweed at the right time with the spraying treatment. As soon as new leaves sprout (which they inevitably will) we’ll have another go at it.

    Beach House Self Catering, Isle of Mull
    Twitter: mullescape

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