Could you please give us some more detail such as when you laid the turf, what grass you used, where you are based and what the weather has been like and/or how much you have been watering? Also, how much sun does the grass get? Is that area typically shaded by the fence?
I'm sure a little more detail will help our knowledgeable members to diagnose the issue.
Welcome to Workshop. We're pleased you could join us and look forward to reading all about your projects and plans for around the house and garden. Feel free to post whenever you need a hand.