CHOPPING UP PULLED WEEDS WITH LAWN MOWER

(Question)

MY WIFE PULLS WEEDS, WITH ROOTS, FROM OUR FENCE LINE, THEN THROWS THEM ON THE LAWN TO BE CHOPPED UP BY OUR LAWN MOWER. I THINK THIS CREATES A LOT OF BABY ROOTS TO START AGAIN. AM i RIGHT ??? OR WRONG

(Answer)

Both … depending on the stage of the weed’s life cycle.  It is not the roots about which you should be concerned, but rather, the seeds. If the weeds have flowered and are producing seeds, then you would be adding weed seeds to the lawn,

But if done before the weeds have set seeds, you should be fine.

The primary exception would be Japanese Knotweed, which can grow back from tiny pieces of root. See the description and explanation here.