This is not good news for Belgium. Although the extent of any invasion is likely to be far less severe than in California due to lower temperatures in Belgium, this aquatic weed is a menace because of its ability to spread rapidly, and the ineffectiveness of mechanical removal strategies at eradicating all plants in a given area. Spread is by seed and stem fragments, and the seeds germinate relatively fast to produce very small plants which can be dispersed by wildfowl, water currents, water craft and even wind. If the current distribution of this plant is limited, use herbicide to treat it before it has a chance to spread further. If it has got to the point where the plants have formed dense mats on the water and manual removal is required, ensure that the material removed is either composted thoroughly, or treated with herbicide to prevent stem fragments from forming new plants.

Thx a lot Aleksandra!! use of herbicides in a watery environment is forbidden over here, but I suppose manual removal of such a small infestatino will do. While we are at it, water managers are more and more confronted with Sagittaria latifolia. Have you got intel on potential invasive character of this one too?

Hi Tim,

I'm not so familiar with Sagittaria latifolia, but good, up to date information can be found at:

http://www.cabi.org/isc/?compid=5&dsid=109160&loadmodule=datasheet&page=481&site=144

Hope this helps!

Hi Tim,

Just wondering whether Impatiens glandulifera isn't a bigger problem then the above?

Not comparing species, just evaluating newly emerging ones that we have little experience with. I. glandulifera is considered a black list species in Belgium, see http://ias.biodiversity.be/species/show/65.