Posted: 02/03/2015 at 14:45
In my experience there's no point in digging the roots out and then spraying what remains - that's doing the job twice.
Just wait until the leaves are growing actively and spray them with glyphosate THEN WAIT UNTIL THE LEAVES GO BROWN AND DIE before digging the bindweed up. If you do it too soon the roots will still be alive and every little bit that gets left behind will grow into a new plant.
You might need to do the job a couple of times, but you will get rid of it by doing the above - we did - and the bindweed had reached the upstairs windowsills when we moved in!
You will probably find that a nearby garden has bindweed and it's spreading via your boundary, so each spring keep your eyes open for the telltale heartshaped leaves around your fence and spray them with glyphosate when they appear.