Have you got a half-moon edging tool? That works well, but so does an big old knife, pushed in to cut the turf along the edge of the concrete. The overgrown turf will pull away then.

As Ojibway says, a half moon edging tool - much easier on the back! Technically, you're supposed to use that tool to take out about half an inch of turf and soil along the concrete edge, probably every spring - then you can get the sideways on long handled lawn edging shears in the gap to keep it trimmed.

I 'think' that you can buy an electric rotovator type piece of equipment that will do the same as an edging tool. However, the edging tool is much cheaper and easy to use.

You're right, Bulbaholic - the contract gardeners here have one - its powered, and like a cutting wheel with a sort of funnel that chucks the bits you've cut up in the air, away from the edge. But usually, I go down and do it properly with the edging shears and half moon edger after they've gone - its not a great finish after they've done it. Maybe it takes practice, don't know.

I use a strimmer on several lawns which grow up to patios/drive ways .

Here's are some examples

http://www.flickr.com/photos/31559373@N00/5009336230/in/set-72057594072815906

http://www.flickr.com/photos/31559373@N00/5009334842/in/set-72057594072815906

http://www.flickr.com/photos/31559373@N00/3529613792/in/set-72057594072815906

like Anchorman I use my strimmer on the edge of lawns. and when cutting along a path I ensure i did it just off the path. Then Mowed to collect debris.

Our garden helper strims our edges, which are butted up to the lawn, and then mows......seems to work really well.

Thanks to everyone for most helpful suggestions. I'll try the strimmer first, as I've got one, and then if need be I'll invest in (or borrow!) a half moon edging tool.

How much have you got to do? I have a bit of lawn that abuts two paving stones - I get the scissors on the go for that bit! Not much good if you have 'miles' of it to do though!! :)