Japanese knotweed is once again in full swing and terrorizing the UK's gardens and countryside, if you're dealing with it yourself you want to have got the first treatment on the knotweed in already. The best plan for tackling it yourself is to use a glyphosate based weed killer (a domestic use herbicide assuming you don't have a license for professional herbicides) and apply it soon after the knotweed has started growing while it's between 0.5 and 1m tall.
Get the herbicide as much as you can on the green matter of the plant rather than the soil for maximum effect and be very careful about any waste which comes from the knotweed lest you cause the plant to spread, which could result in you being prosecuted since it's illegal to cause knotweed to grow in the UK. When disposing of waste it's important to remember waste could be on tools or shoes. Any waste you do have should either be left where it is or disposed of as controlled waste. Under no circumstances should it be composted, thrown away with normal waste or, god forbid, fly tipped.
After the first treatment, treating again later on in the season can help to speed up killing knotweed and even up to a third time. You should expect to have to repeat this process for several years however; knotweed is a tenacious plant and to get rid of it, you need to match its patience. If you're unsure when dealing with knotweed yourself at any point, don't hesitate to contact a professional and get advice on how to deal with your case of knotweed.
Also, if you see Japanese knotweed on the side of the road or near your home, you should contact your environment agency and let them know so they can make sure it gets dealt with; the longer it's left and not known about, the more it will spread and the harder the job of getting rid of it will be.
