how fast does Japanese knotweed grow

How Fast Does Japanese Knotweed Grow?

If you’re wondering “how fast does Japanese knotweed grow?” you may have found knotweed near your property. Find out how fast it grows and how to stop it.

You aren’t alone in worrying about Japanese knotweed. Despite years in the public spotlight, knotweed continues to spread throughout the UK.

Scientists found that in Japan the knotweed was controlled by its natural predators. These predators don’t exist here, so when the plant was first introduced to the country, there was nothing to limit its spread—or the phenomenal growth of its shoots, which has become quite infamous.

The UK’s fastest growing invasive plant

Japanese knotweed is the UK’s fastest-growing invasive weed. During the summer, which is its peak growing period, it can grow at speeds of 10cm a day.

This means that emerging shoots might not seem like much of a nuisance at first, but they will quickly grow out of control if left to their own devices.

The BBC reported that the plant grows during the growing season by as much as 1 metre in three weeks. Although not insurmountable, it is a severe problem that certainly needs addressing.

How to stop Japanese knotweed growing

Really, there are only two ways to permanently eradicate Japanese knotweed: to apply a glyphosate-based weedkiller or to dig the roots out and dispose of the waste. The problem here for homeowners is that the plant can only be disposed of at licensed landfills.

The smallest sliver of a stem can reproduce. This makes eradicating the weed an ongoing process that often takes three or four years of treatment applied three or four times a year.

To speed up the process, stay on the right side of the law, and avoid years of stress, you are almost always better off approaching a professional knotweed removal service.

Found knotweed at home? Arrange a free site survey and get a tailored quote.

Reduced house prices, property damage, and more

BBC News reported in 2010 that knotweed was costing taxpayers about £150 million per year. Estimates have zoomed higher as the plant has closed in on residential property gardens and landscaping and disrupted water lines and housing foundations.

Japanese knotweed has troubled homeowners, given mortgage lenders cause for reconsideration of loans on properties infested with the weed, and caused homeowners to lose value in their biggest asset.

By exploiting small openings in pipes or crack in a barrier like concrete and expanding, the plant damages and sometimes even breaks these structures apart.

Threat to local wildlife and plantlife

In addition to spreading wildly, this prolific grower is a threat to local biodiversity, overcoming any vegetation in its path. It also pushes wildlife to new environs that are not as safe as their natural habitat.

There has been speculation about bringing the insects into the UK. R Dick Shaw told the BBC, “Safety is our top priority. We are lucky that we do have an extremely specific agent – it just eats invasive knotweed.”

If you suspect you have knotweed and are uncertain or anxious about how to proceed, we can come and take a look for free – no obligations. If you enquire now, we can be with you in less than 48 hours. We’re here to help.

Book a site survey with on of our Japanese Knotweed specialists.