My lawn is 20 m x 20 m . On three sides there is a gravel path and on the fourth is a flower border . On the sides with the path, about 18 inches into the the lawn it starts to slope down to the gravel preventing me from getting a nice defined edge to the lawn .I have seen lots of public gardens with a similar arangement but the lawn stays level and doesnt slope away at the edges . Any explanation ?
Presuambly, when this lawn was made, it was sloped down at the sides, or if this was not done intentionally, it was left soft and subsequently slumped outwards to its current level.
It you want it level, you must change the soil level, raising it to match.
This can be done, either by lifting the existing sods back far enough and a machine can be hired to do this, and filling before putting them back, or filling with soil on to the exisitng grass and sowing on top of the new soil, in both cases firming well.
In the second case, the matchof the new seed with the existing lawn might be difficult and you might have to re-sow the whole lawn.
This can be done easily without cultivation, but killing the existing lawn with Roundup and sow the new grass seed into the dead sod.