Dark Patches on newly laid lawn
We laid some new turf in a part of the garden about 6 weeks ago. Underneath the turf we put plenty of topsoil down on top of the muddy/sandy stuff that was already there.
We watered the new turf twice a day and only mowed it when it got particularly long (but at a high setting on the mower).
I noticed some dark patches on the grass over the last few days and was wondering if anyone could suggest what the patches might be? Is it anything to be concerned about?
Some photos below.
Thanks in advance.