Clarke Brunt replied:
Definitely the gardeners who are at fault, and the people who sell them the leylandii so readily and cheaply.
I have a nice maintained row of them too - it looks good, and it means that the panel fence behind them no longer blows over at the slighest sign of a breeze. But it's hard work. They grow quickly, and should I ever stop my voluntary maintenance of this leylandii hedge (which isn't even in my garden!) then the usual gloomy, unsightly, water-sucking monster would result within a year or two!

Chris Wilson asked:
How far apart do I need to plant 5 foot Leylandii plants to ensure a hedge growth that is visually opaque? Any tips on how deep and big the holes for these plants should be?

David Poole answered:
Planting 5 foot specimens offers absolutely no advantage over smaller sizes and in many cases can create a much poorer quality hedge. Leylandii never seem to thicken up that well if planted out as big specimens and I know from countless instances, that good root development rarely takes place.
Leylandii hedges have a wonderful tendency to collapse like a pack of cards in very high winds and more often than not, this is due to over-large plants being used in the first place. Whatever happens, Leylandii sit for a while and then start to take off. The bigger they are to start with, the longer they take to get going. You can plant 24 - 30" specimens alongside 5 or 6 footers and after 3 years, the smaller plants will have not only caught up, but will be more dense and appear a good deal more healthy.
Pot grown Leylandii are often fairly pot bound and you should lightly tease impacted roots away from the outermost parts of the root ball before planting. Alternatively, lightly slashing the outer roots with a sharp knife will also encourage new roots to grow out into the surrounding soil. You don't need to stab or hack deeply, simply a few, light cutting strokes will cause those roots which have been severed, to form masses of new ones.
Now planting centres for Leylandii can be as little as 2 feet, but root development will be impeded by competition from the other plants resulting in a less stable hedge later on. Ideally 30 - 36" is best. Take out holes at least half as deep and wide as the root ball (or pot size) and mix a good amount of garden compost with the soil. Partly refill so that the plants sit with the top of the rootball just below finished soil level and then fill in around the roots. Lightly firm in and make sure that in the first year at least, your hedge does not want for water in dry weather.

Pete The Gardener wrote:
In the first year a three foot laylandii will grow about a foot, a five foot one will grow about four to six inches, in the second year the three foot one could grow as much as six feet whilst the five footer will only grow about a foot. Small plants also form a denser more stable hedge with less chance of the whole thing blowing over. As for planting distances, although it will look far to wide when you set them out I would sugest that you leave at least four feet in a single row or three feet if you are stagger planting.
By the way, remember to start clipping them as soon as they start growing as this will help thicken them up quicker. When they are established you will have to clip them about five or six times a year to keep them under control, don't forget they will grow to about eighty or a hundred feet if left to their own devices.

Sacha weighed in with:
Many posts to this ng are from people who have 'inherited' leylandii that have been allowed to get out of control. These are, basically, forest trees - they just go up and up and up and they are NOT suitable for most people's gardens - if people planted an Ash they'd get the same result eventually because it's a forest tree. The only difference is that it's slow growing - but it would produce just the same headaches in terms of light restriction.

Chang replied:
Unless you live in a particularly cold area, cut it back at any time that suits you. It should survive the experience. It will not regrow from old wood so make sure you leave green shoots everywhere that you want regrowth.

Nick Wagg said:
You will have to cut out the growing tip *every* growing season as this is not just a one-off treatment. You might manage with some stout hedge shears in the first year or two but you will soon need to invest in some sturdy loppers too.
If you miss a year, the job will be that much harder the following year.

Stuart Grant wrote:
My Leylandii was up to 10ft in about 7 years. They need a twice yearly cut, May and September, and an occasional extra topping-out as the established top cut will creep upwards as the hedge matures.
When you let them grow as they will, the growth is concentrated up one stalk which will put on more height each year as the root system develops, but when well cut there will be many stalks taking a share of that growth, and so will reduce the overall annual height gain to less than a foot in my case, and my hedge is about 12 ft high and 16 years old.
When establishing a LL hedge, it is important to cut the sides back to keep the growth close to the trunk, or they will end up taking a lot of space and hollowing out in the centre. Take the growing tip off the top each spring to encourage them to thicken out as they grow, don't let them get up to height and then let them thicken out, it'll take twice as long to form a proper hedge that way and you'll be wasting growth by having to cut it off the top where it's not wanted.
It's also a good idea to intertwine the side branches as they grow to bind the adjacent plants to each other, as a storm can easily pick one out of a row, and you'll find it takes ages to grow a replacement where the direct light is restricted.

If a neighbour's hedge or tree hangs over your garden you are legally entitled to cut back any growth that overhangs your side of the boundary. Naturally it is good manners to speak to your neighbour first. If it is an established tree you should first check with your Local Authority (LA) that it is not the subject of a Tree Preservation Order (TPO) or Conservation Area protection.
The branches and any fruit on them remain the neighbour's property and you must offer them to him. He is not obliged to take them however and if he refuses you must dispose of them properly yourself - just throwing them into his garden would be very unwise!
If the neighbour's hedge is so high that it causes you a problem, and a friendly approach to him does not succeed it getting it trimmed, you may have a remedy through the LA.
For this to succeed you must be be able to show that the hedge is evergreen (eg a Leylandii), that it is more than 2 metres high, and that your 'reasonable enjoyment' of your property is being adversely affected. You must also demonstrate to the LA that you have taken every reasonable step to resolve the matter directly with your neighbour before approaching them. If the LA find the hedge to be in breach of the regulations, they are empowered to enforce its lopping.
Before taking formal action you should consider several points: The Local Authority are entitled to charge for taking up the matter. Most of them do, and their charges can be substantial. Starting a dispute with your neighbour can cause future problems in other ways, for instance if you ever wish to get their agreement to a planning matter. And when you come to sell your house you must inform prospective buyers of any such dispute.
NOTE: The above represents only a layman's understanding of the law. For a definitive view, consult a solicitor!
The relevant legislation (Section 8 of the Anti-Social Behaviour Act 2003) can be read here

Ann Taylor wondered:
If my neighbours move, can these trees still reach the sky if not kept in check? Please answer False.

P.Bridge commented:
We had 5 trees all about 40 - 50 foot high cut down for £10 each. We left trunks about 6 foot tall that are now the basis of a rose rope. Any shoots are easy to remove with secateurs. However, that is the easy part. Don't undersetimate the amount of work in getting rid of the "brash". We have a LARGE shredder that reduced everything to shreedings that now smother the beds. You can probably hire one for a few days from a tool hire shop.

Mungo Henning said:
Someone awhile back mentioned using a power-washer to blast away the soil around the root-ball: helps identify all the little tethering roots!

Sacha commented:
I've just done exactly this with 60' of hedging. Because the roots ran under a low wall and then a road, we couldn't get the stumps out and have used the drill and stump killer method. I think it's called Root Out. I don't know about the risk of Honey Fungus but that usually (not exclusively) attacks diseased or dead trees and hopefully, the Root Out will do its thing before that becomes a danger.

Jane Ransom answered:
How big is the access to the trees?
We found a jcb much the best method.
Picks the lot, rootsanall, up out of the ground :))))))
It was well worth the £100 per day to stay clear of the backache! Of course we had to dispose of the bodies afterwards but that was relatively easy and could be done bit by bit over a longer timespan :))

Rick replied:
I used a ratchet winch. You drive a couple of pinch bars into the ground and hook up winch to these then the other side of winch connects to chain which you wrap around the stump - work the mechanism back and for and it will pull out anything. Most of the big hire shops will hire them.

Chris French suggested:
A mattock please. Much more useful for this task - and for many others around the garden.

Jack Pease told us:
I borrowed a transit and towed mine out. It was big, and you need a serious rope, but boy it was fun.

Mike continued: Don't cut the stump off level with the ground. Leave about 3 - 4 feet of stump sticking out of the ground. Cut a peripheral vee groove about 6" down from the top using a chainsaw. Dig out and expose as much of the root ball as you can. Tie a stout rope around the vee groove, attach other end of rope to someone else's vehicle and tow it out as suggested by Jack Pease. Setting up a rocking motion can be effective. The length of the stump above ground gives you a decent leverage allowing you to 'rock' the root ball and tear it free.
You'll probably have to cut some major roots, especially those which are directly opposite to the direction you are towing. You can dig them out later. Have fun and remember to include for a new clutch in your costings :-)

Charles (Joe) Stahelin suggested:
If you have no friendly vehicle owners hike off to the local hire shop and get a ground winch. These are quite small and easy to work but a good ground anchoring point is essential plus chains/ropes cable. I imagine you could get the lot from the hire shop if necessary. If my memory is right I think "Tirfor" is the name of one breed of suitable winches and their generic name is "Monkey Winch". Safety: make sure everyone other than the winch operator stands well out of reach of breaking chains/ropes/cables.

Pam added:
We've had a succession of bonfires over the past couple of years - once they get hot anything (well nearly) will burn! Best tecnique we've found so far is to soak a couple of old T-shirts in paraffin and build the bonfire around them. Last fire we had disposed of 6 complete trees (admittedly they were only babies, about 7' tall with 5-6" diameter trunks, and came out pretty easily with the help of a mini JCB).

Tony (Partner in tree-felling Co) gave this advice:
1) If you were to fell the trees in one piece, is there anywhere where they can come down in one length?
If so, some of the advice in the preceding posts is good - as far as it goes. Cut the lowet branches off close to the trunk up to a height which will allow you to work comfortably beneath.
2) Attach a rope as high as you can on the trunk. (Within reason! You will be pulling on this!)
3) ON NO ACCOUNT cut the trunk. Dig round the base and cut as many of the roots as you can find.
4) Now get someone to haul on the rope, and rock the tree. You will see the earth moving above hidden roots. Cut these with a spade, mattock or (if you must) a pick.
5) Keep doing this until the tree gives up and falls over. You may have to allow it to fall gently (against a shed or fence if necessary) which a small tree which you describe will do if it is still attached to the rootball.
6) NOW you can cut the trunk across.
7) And the rootball can be de-soiled and pulled out.
Always leave as much of the tree as you can if you are taking the roots out: the higher the attached rope is above ground the greater leverage you can apply. A big root under tension will be cut far more easily than one which isn't, and two people can easily do a job that would otherwise be very hard work for several.

Dudley wrote:
1st thing to do is make sure that there are no birds nesting in the trees, second thing to do is make sure you are wearing very old clothes as the sap in Leylandi is difficult to remove from clothes (and skin).
You wont be needing the axe, and probably not the chainsaw either until the trees are down on the ground. Cut away ALL the branches flush with the trunk to a height of about six feet. If you dont cut them flush you will constantly snag clothes and skin on the bits left behind - they are hard and sharp!
Put a rope around the tree as high up as you can - 10ft or so. Attatch two friends to end of rope and tell them to pull. Use handsaw to cut through tree trunk about five feet from ground starting from opposite side to rope.
Its then time to start digging around the roots. You can get hold of the top of the tree to 'rootle' it around to loosen up more soil around the roots. From past experience the roots are generally fairly shallow, but can run quite a distance, especially if they are growing towards a source of water. They also seem to have a central tap root which goes straight down. Although the roots are fairly shallow the stumps dont usually come out without a fight. The secret seems to be to keep digging, I found using a crow bar to break up the soil around the root ball and scraping out the soil with a trowel very useful, you need to get as much of the soil off the roots as you possible can - soil is bloody heavy!
Don't cut the trunk below 18 " high. Then have a good excavation and hack at the root area around the trunk, using a pickaxe and spade, saw through the thick roots below gound and use the standing stump as a rocking lever to loosen the root ball mass until you can cut it free and lift it out.It makes that job much easier.Once you have the main root and stump cleared out of the way, if you want to site the pond there it will be relatively easy to get out any remaining sawed off roots as you dig the hole.
Stump killer would take very many years to disintegrate the roots, no good for your pond idea.

And finally, someone with obvious first hand knowledge added:
If the trunk is of a reasonable thickness - say above 8 inches?, it's better to cut a 'birdsmouth' out first on the side you want the tree to fall. Saw in horizontally about a third of the trunks thickness, then saw down at an angle from above to cut out a wedge. Now saw in from the other side horizontally, a little about the point of the birdsmouth.
Try to cut in evenly, if you cut in nearer to the birdsmouth on one side than the other, when the tree starts to fall it will twist (you can of course use this to you advantage if necessary).
What out for it 'sitting back' on the saw (the friends on a rope can help here), or for it jumping off the stump - usually happens when using a chainsaw, as it's easy to cut to far, it starts to fall, the wood snaps and it slips off onto your foot. - once it starts to fall, stop cutting - get out of the way and let it go. a slow fall also means that the rope holders have more of a chance of directing the fall if necessary.
If you are using a chainsaw, please use the correct safety gear, minimum - steel toe capped boots - spats if not chainsaw boots, protective trousers and gloves, helmet with visor and ear protectors, a protective jacket is good too, which protects against the saw kicking back, but this isn't as common as people sawing into their legs or feet.