Posted: 24/09/2016 at 08:55
I agree, it's not Mare'stail.
Whatever it is, I think you have two choices:
1. give the area a good digging over, removing every tiny piece of root - prepare your lawn and sow your grass. If any bits of whatever it is reappear next year as long as you mow regularly it shouldn't cause a problem.
2. spray again with glyphosate and leave - sow your grass in the spring.
Last edited: 24 September 2016 08:56:32