ref grass dying thankyou for any awnsers

If it is only along the edging then it seems it can only be one of three things

1. the edging in some way is killing the grass..this sounds a bit unlikely. Have you put new edging down recently?

2, You have applied something to the garden or path side of the edging ? Weed killer or pathclear. Pathclear in particular can leach across from the treated area into an area you don't want treated.

3. If you are in the middle of a drought( you don't say where you are in the world) often grass against edging goes brown first.

I can't think of any other likely causes.

Agree with Anchorman's comments, except I see you are in Bedfordshire, lol! If none of his suggestions match up, let us know what the 'edging' is...

we sometimes get red ants nests at the edge of the patio /grass the grass does tend to go brown in patches then

Strimming it to close to the ground ?!?

thanks for all the replies to my last question ref grass dying at the edges

has anyone any idea how to keep ants from my lawn iv got them spreading like wildfire I live in beds area ant powder doesnt seem to work

You can get a nematode treatment for ants in lawns - not sure how effective it is, never used it. Google Nemesys, should be one of the ones available - if not, google nematodes for ants.