"David Hill" wrote in message
...
Without doubt Persicaria.
Get rid of it, whilst it can look nice it seeds very easily and will be
coming back for years.
Also it can grow almost 2 inches in a week .

Thanks for the warning, I'll be digging the lot up tomorrow. I already have
a worthy adversary in the garden - Bindeweed. I can do without another! Is
ok to compost at this stage (Persicaria) or should I burn it?