"BCL" wrote in message
...
I was busily spraying the gardener's best friend (Roundup) along the
fence and various other places when it occurred to me to wonder if it
is more effective sprayed in the morning or evening or even mid day.

I have had (rare) occasions when the spray has had little effect on
the weeds/grass and wonder if the plants absorb it better at some time
rather than others. This doesn't include it being washed off by rain.


Any thoughts?

Regards
Bruce

It is generally best to spray in the morning, before the leaves get too
warm, because they then close their stomata (pores on the underside of the
leaves) which it is commonly thought is how plants take up nutrients.