What kind of grass are you sowing, Sunshines? It sounds like it is going annual on you, or you may have a lot of annual weed grasses out-competing it at the start.

hi tugbrethil i sow a mixed seed hard wearing i think its got rye in it it is perenial grass seed thanks for your reply

Is the area well-drained, Sunshines? You say it goes muddy - maybe that's the problem, or is it too shaded? The other thing you haven't mentioned is the use made of the lawn. Is it heavily used by human feet or dogs maybe? If that's it, then keep them off until the grass is established.

If it's too damp an area, then you'll need to spike it all over with a garden fork and brush sharp sand into it, or very fine compost.

If it's shaded, there is a special grass seed for such areas.

hi spritzhenry yes it is under a big tree i will try seed for shaded places thank spritzhenry

That explains it, then. Glad to be of assistance. :-)