On 23 Oct, 22:15, Janet Tweedy wrote:
In article , Martin Brown
writes

Why buy it now? The weather is already too cold for it to have a full
effect - applied at this time of year is a waste

Many of the more stubborn weeds inc. Japanese Knotweed are considered to
be more likely to be affected by poison if sprayed as they are winding
down for the year as they take the stuff into the roots.
--
Janet Tweedy
Dalmatian Telegraphhttp://www.lancedal.demon.co.uk

There is the alternative that you never hear of now which is to mix
the concentrate with parafin. Penetrates a lot better.