Populations of herbicide-resistant broad-leaved weeds are still uncommon in the UK but are increasing. If you suspect resistance, collect seed samples for testing.
Although resistant populations of broad-leaved weeds (BLWs) are relatively rare, they are increasing and, as known from black-grass and experience overseas, prevention is better than cure.
In the UK, resistant poppy is the most common, followed by chickweed and then mayweed. Most cases of resistance are to the ALS inhibitor group of herbicides.
The publication covers the current distribution of herbicide-resistant BLW populations, along with information on the non-ALS chemistry that is currently effective.
Guidance on how to minimise resistance risk and how to follow up and investigate the root causes, where weed control, has been judged to be poor, is also included.