On 30/06/2010 18:28, Phil Cook wrote:
Martin Brown wrote:

On 29/06/2010 22:03, Geoff Lane wrote:
Following earlier advice in this forum I am putting bindweed leaves into
a polythene bag and then spraying into the bag securing with a tie.

Isolated growths I am just spraying.

When would the root be effectively dead allowing me to dig in or pull up.

One hit won't do it. If you have a lot of the stuff then there is some
slight mileage in letting it get tinder dry and then torching the top
growth - taking care not to burn fences or adjacent plants.

The instructions suggest a few weeks but can a dieing plant recover or
is it effectively dead once the leaves start to shrivel.

One hit will not kill the roots of bindweed. After 3-4 weeks they will
be up with new shoots and you will need to hit it again. Then give it
another couple of weeks and try digging out what you can.
Glyphosate may not kill it but it does weaken it to the point that small
pieces will not regrow - same is true for ground elder (which is easier
to kill).

Is it not likely that the best time to treat it will be late summer to
early autumn before the frosts have killed the top growth? Since then
it will be sending sugars down to the roots and that will promote the
take up of glyphosate into the roots. That is what is recommended with
Japanese knotweed. I'm biding my time on a major clump of that at my
brother's place.

Not quite.

If you don't mind using things off-label (technically illegal) then
using glyphosate dilute 2x more than normal will allow more time for the
transolocation before the top growth dies. And is cheaper if you hit it
every couple of weeks. You do not want to allow any leaves of bindweed
or knotweed to see the sunlight without being sprayed.

Hit it. Hit it and hit it again every two weeks through the growing
season. Doesn't really matter what weedkiller you use either just do not
let it get good leaves in sunlight. It will store energy in the
extensive roots from the moment it has two leaves above ground!

Regards,
Martin Brown