Interestingly, Japanese knotweed in the UK is from the female clone and is therefore incapable of setting seed, yet is still able to spread at an alarming rate if untreated. Read more here: https://www.telegraph.co.uk/gardening/plants/11285502/Do-plants-have-a-gender.html
Experts from the PCA’s Invasive Weed Control Group are to showcase 14 of the good, the bad and the ugly invasive non-native plants which are currently thriving in gardens across the country at this years RHS Chelsea Flower Show. Click here to read more: http://press.rhs.org.uk/RHS-Shows/Chelsea/Press-releases/Invasive-plants-to-take-root-at-RHS-Chelsea-Flower.aspx
An interesting formation of Japanese knotweed I found last week. Its a little stressed but leaves should unfold in the next week or so.
Actually they are very similar plants and smell gently of garlic if you brush past them or their leaves are crushed. Unfortunately they can spread quickly and overtake our native garlic species Ramsons or Wild Garlic (Allium ursinum or Allium vineale)!