If the site is a commercial site, you may want to think about excavation as this means the site can be developed immediately with no risk of the Japanese knotweed interfering with the proposed development of the site. Typical costs are £10,000 to £15,000 but it can be considerably more depending on the size and accessibility of the site. This, however, can be an excellent choice if the Japanese knotweed is stopping the sale or inhibiting the project.

The majority of residential houses opt for treating the Japanese knotweed with herbicides. The chemicals we use are 300 x stronger than those available to the public and we apply these through injection and spraying. This method takes three years followed by monitoring of another two years to ensure no regrowth. This method is more cost effective and typically cheaper than excavation. Typical costs are £3,000 to £5,000 however we have completed jobs that were £2,000 and over £10,000! The cost is dependent on what we find during the survey of the site.