a picture would sure help .. and we surely need to start with a full ID ... as you seem to be guessing ...

and beyond that.. i dont know why you would want to mess with the landlords plants ... is he going to give you a months free rent for this god forsaken project???

just height reduction???

ken

Very likely is Cupressus x leylandii. And no you won't kill it by taking out the tops. Your neighbours will probably be keen on the idea too, especially if they are on the northern side of it. Maybe talk to them? You have the law on your side. A 'High Hedge' is over 2m.

Here is a link that might be useful: High Hedges Legislation

As the tree involved is a conifer taking too much off could, in fact remove its ability to keep producing new top growth- there will be a certain height beneath which it will be unable to sprout. And thinning it out is a bad idea as a dense screen is the point of such a hedge.

These things are so vigorous here that they are regularly topped and also sheared. Doesn't seem to bother them.They are generally grown for hedging, not as trees and people have no idea how big they will eventually get. There is a golden one behind our house which we asked to be topped because it blocked our sunlight.They removed about 3 metres. It didn't miss a beat. Just got a little dumpier and started growing a new leader.

If the hedge is already 12 -15 m high it is not going to stop. It has to be tamed before it is too late. As the link showed it is actually illegal to allow a hedge to get over 2 metres if neighbours complain.

This post was edited by flora_uk on Wed, May 1, 13 at 14:49

I'm not expecting topping them to be overly difficult- should be able to stand on a ladder with some loppers. Should be able to do it over a weekend (whereas cutting them down would leave me with several tonnes of tree to dispose of).

I have already trimmed the hedge back on my side, and think I might have overdone it a bit as all that seems to be left is bare wood and dead leaves. When I did it I thought this would regrow but have since read that it won't.

It may seem strange to spend so much effort on someone else's garden but they were in such a state when I moved in that they were irritating me. Given that my lease says I am meant to maintain the garden and the landlord did mention trimming the hedge I thought I'd give it a go.

Will upload a picture tomorrow.

Here's a picture of the hedge

Another angle

Is this overtrimmed?

You might have trimmed too much. A twig with no green left will die, conifers does usually not break new growth on old wood like many decidious trees do

I've read somewhere that if a section is overtrimmed you can pull the branches through from the other side of the hedge. But is this really feasible as a long term solution?

Whoopsie!

Mmmm - didn't realise you'd already trimmed the sides. But you still need to take the tops out. Then cross your fingers and wait. Classic example of where not to plant Leyland Cypress.

Fits into any space if you start shearing when small, and keep it up. Now there is a dwarf cultivar being sold in my area. But it looks like it falls open, based on what I have seen here.