A large succulent, annual introduced in 1839 to Kew Gardens as a greenhouse plant, it escaped to the wild, now naturalised in the British Isles and many other non-native countries - it is very invasive and should be removed when found. It is in the same genera as the colourful, bedding Impatiens or Busy-lizzies, but grows much taller - up to 2 metres high. Preferred sites are moist areas, usually along river banks, but it colonises many other areas. Dense stands suffocate other plants so when it dies away in the winter, river banks are left bare and more liable to erosion. |
The main aim in controlling this weed is to prevent it setting seed. It is easily uprooted and cutting below the lowest node or at soil level should prevent it from resprouting. Cattle and sheep graze and trample the topgrowth.
Weedkillers to use:-
Glyphosate kills the plant, but must be applied at an early stage well before flowering.
2,4-D amine is selective so underlying grass should survive application, thus improving soil stability and a dense cover of grass will inhibit further germination.
Follow these links for further details on Weeds, Weed Removal and Weed Prevention.