What hedge is this?

Are you certain its evergreen? Because I've a feeling its Forsythia...

Sorry, I completely lied - or rather my wife and my memory lied to me! After searching my photos I've found one and it isn't evergreen at all!

I don't recall any yellow flowers either though - should it have them if it's Forsythia? It is in a bit of the garden that we rarely see.

It certainly looks like Forsythia to me, too. Maybe pruning it has cut off the flowering branches?

I'd say you're removing the growths which would flower when you cut the hedge - forsythia should be cut back after flowering, and if you do it in, say, September, you're removing growths which would have flowered the following spring. Forsythia's usually planted as an informal hedge rather than a formal, clipped one.

I have a picture from this time last year when we moved in before it was cut. There were no flowers on it then either (it looked exactly the same as picture 2 to me, but 3 feet higher).

All the pictures on the internet show it covered in yellow flowers - should these last throughout the summer or are they only present for a few weeks?

Anyway, assuming you're all right (thanks) it is Forsythia (I agree, the leaves and stems do look exactly like it, now I know what to search for), when should I cut it? Now?

No, not all summer - its a spring flowering shrub, often in flower very early on, around March/April for about 2 or 3 weeks.

It is possible to cut Forsythia later than is usually suggested if you are careful not to trim off all new growth .

I trimmed a forsythia immediately after flowering last year and then because it was encroaching on a path and I was requested to do so I trimmed it again around late July /early August) . I was very careful to leave at least 2-3 inches of the growth it had made between spring and when I cut it and it was full of flower this spring.

You don't need to buy extra plants as they root incredibly easily. Cut off as many branches as you need and sink them into the ground by about a quarter of their length. Leave them over the winter and they should nearly all root.