OK not really that drastic, not compared to some that I've done *laughs*, but here's a nice small-scale example of how to tame a Box hedge that has is getting away from you.
The hedge here goes "round the corner", so that from the outside you can't really see that there's a gate there at all, for security.
However, visitors were starting to complain that they couldn't get the gate open, especially when the hedge was wet!
The hedge has been trimmed regularly, but this demonstrates the sneaky nature of clipped hedges: unless you are really strict with them, they will gradually grow further and further out, until they take over the entire path. Yew does it, Box does it, Lonicera nitida does it (really quickly!) and the answer is always the same - every couple of years you have to be brave, and speak severely to them. Just running the hedgetrimmers over them is not enough, as most hedgetrimmers will only get through the softest, most recent growth.
This was the problem with this small hedge: the owner has a dinky little battery-powered hedgetrimmer which is simply not man enough for the job. (Another reason why I prefer to use hand shears.)
So, what do we do?
As you can see, the bit on the outside is growing a long way beyond the gate post, and furthermore it has been allowed to grow top-heavy, giving the impression that it is leaning outwards.
This is bad horticulturally: hedges should always slope the other way, getting narrower at the top, not the bottom.
This allows light to fall on the whole side of the hedge, so that all of it will grow and thrive.
By letting it loom like this one, the lower part of the hedge gets little light, and grows only very slowly, while the top section grows ever more vigorously, so the problem just gets worse and worse over time.
So, step one: chop into the over-grown section.
You can use string, or a cane, to get a straight line if you need to, or you can just do it by eye.
To cut those thicker stems, you'll need secateurs, and occasionally loppers. Cut them one at a time, and try to keep a fairly straight line if you can - but don't worry too much at this stage.
This shows the first cut about half-way done.
Here we are five minutes later, the outer edge of the hedge is now upright again, and there are three bucketfulls of cuttings in the green bin now.
(Don't compost them, they don't rot) (well, everything rots if you leave it long enough, but don't bother adding them to your normal compost pens!)
As you can see, the very bottom of the hedge is still narrower than the top, because it had been overshadowed for quite some time.
But it should grow back now, now that the light can get to it.
Here's the same thing from the side-on angle, to show how what appears to be a solid hedge is actually a framework of bare brown branches, with an outer layer of green leaves.
This is absolutely typical. Most dense hedging looks like this, if you gently part the outer leaves: and if garden owners don't realise this, it can give them a nasty shock when they see a newly cut-back hedge!
Luckily, Box, Yew and Nitida all share a wonderful feature, in that they will "green up" if you do this to them - unlike the unlovely Leylandii hedges, which are famous for staying brown and hideous forever, if you cut them too far back.
No, these classic hedging plants will leaf up in a few weeks, which is why they are so popular for hedging.
To finish this job, I gave the rest of the hedge the usual spring clipping, to level it and neaten it: then I carefully cleared up all the mess, shaking the hedge to get all the loose bits off, and cleaning out underneath it as well.
It then receives some feed - growmore, or liquid seaweed feed - and a good watering, to give it a head start: and in no time at all, it will be green and lush again.
If you want to see what this process looks like on a bigger scale, I spent three years getting a Nitida hedge into shape, here is the article about it.
So there you have it, how to get a hedge under control - and now the visitors won't get wet hands when they open the gate!