Japanese Knotweed

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Japanese knotweed is a dangerous plant that can cause structural damage to your home. This information will help you to understand what to do if you have or think you have it near to your home.

As your landlord it’s our responsibility for treating Japanese knotweed but we’ll need to work together. We need you to read this guide to make sure that the problem does not spread further, or cause any more damage to your garden or home.

  • What is Japanese knotweed?

    This is what’s called an ‘invasive weed’. It was brought into Europe from Asia as a decorative border plant in the 19th century. It’s now a real problem in urban areas because it can grow very quickly and cause all sorts of damage to structures - such as concrete and pavement.

  • What does Japanese knotweed look like?

    A young plant sends up small shoots that look similar to asparagus and can vary widely in size. The most recognisable thing is their red stems and heart shaped leaves. More mature, unmaintained plants can reach 5 metres in height and spread over a wide area.

  • Is Japanese knotweed dangerous to humans and animals?

    No, in fact in Asia, the plant is eaten in its young state, apparently tasting similar to a cross between rhubarb and asparagus. This is not recommended though.

  • What should I do if I find Japanese knotweed in my garden?

    Do not under any circumstances be tempted to cut it down. This makes the plant grow and spread faster. Walking over it can also spread its growth. It’s very important that you don’t try to dispose of it yourself. This is illegal, and you can be prosecuted for doing so.

    Instead, get in touch with us and we’ll treat it as part of a managed programme of work to remove it from your home.

    Treatment can take a long time, but we’ll work together to make sure your home is safe from this dangerous plant.

  • Can I use my garden while it is being treated?

    Yes you can. However you must stay out of the treatment area which will be fenced off with temporary fencing and warning signs.

  • What is the treatment for Japanese knotweed?

    The plant is treated with a weed killer called glyphosate, either through injecting the plant or by spraying.

    In the winter the dead stems will be cut and shredded back onto the same area. This is to give us access to spray the new shoot that come through. Shoots should reach at least 1m before chemicals can be applied.

    There will normally be 3 chemical applications per year: spring, summer and autumn. This process will be followed each year until we have no further growth coming through.

    We know that Japanese knotweed can lay dormant under the soil for a number of years, so the affected area will be monitored for several years after treatment has taken place to ensure that it has been eradicated.

  • Are there any restrictions on using my garden after that?

    Yes there are. While you are free to make use of all the space in the garden we would ask that you do not dig

    or disturb the affected Japanese knotweed area.

    For example:

    • Do not dig into the soil to put in new plants • Do not excavate out a shed base or any other structure of this type

    Instead:

    • Use plants in pots • Put turf down over the area • If installing a shed install the base on the surface of the soil • Keep your garden well maintained to reduce the chance of re-growth

    DON’T

    • Don’t cut down or remove any Japanese knotweed • Don’t dig your garden in the affected Japanese knotweed area

    DO

    • Make the most of your garden understanding the restrictions above • Keep an eye out for any new growth and report it immediately

  • Could it come back?

    Unfortunately yes, there is a possibility it could. If you believe it has come back, let Midland Heart know and we will carry out some more treatments until it is removed.

  • What to do if you believe you have Japanese Knotweed in or around your property?

    What to do if you believe you have Japanese Knotweed in or around your property?

    Please fill in this form.

  • Who do you use as your specialist?

    Midland Heart works closely with our contractor Japanese Knotweed Specialists.  They use their professional expertise to identify and remove Japanese Knotweed in a timely and safe manner.