Just had a pop-up on my screen saying 'Win a cutting edge lawnmower'.
I'd love a lawn mower that trimmed down the borders of the lawn too.
(I've been getting pop ups for a ride on mower - a bit excessive for our needs!)
I used to look after a garden where they had a " spin trim lawn edger". I've just googled it and saw one sold on ebay recently for £5. It was about the size of child's shoebox, charged up and then walked round the edges via a long handle. Worked a treat.
I do the edges of the back garden and also my allotment with long handled edging shears. I love doing it as it is the icing on the cake and makes all the boring grass cutting worth while.
Unless you enjoy doing it, like Forester2 Edds' idea works beautifully