Posted: 14/06/2012 at 23:36
Roundup is most effective when weeds are been and growing, so the temperature and humidity can effect how long it takes to work. Another factor to consider is the size and type of weed. Larger perennial weeds with deeper roots will take longer than small annuals. Another point to note is that Roundup gel doesn't include that fast acting formula that is in the ready to spray Roundup, so it may appear to be taking longer, as will the Roundup concentrates that you mix up yourself. But be patient, Roundup will work eventually and depending on the temperature, humidity and size of the weed and it's roots, the kill should take between 7 and 21 days. Happy weeding.