In most locations, the law allows you to prune off any parts of a neighbor's tree which cross the property line! So find out where you stand legally. The trimmed hedge would look pretty ugly from your side, but you'd have your space back.

How wide is your yard? What percentage have you lost the use of? How much wider will the lost area be in another 3 or 4 years?

Note that the Leylands will continue to grow at the same yearly rate they've been growing thus far. Also, their roots extend over the property line about as far as their branches, and so steal moisture from the plants in your yard.

Your lawyer might have some advice.

[My neighbor planted Leylands along the northern edge of his property, which is my southern boundary. After 15 or 20 years, they're ... well, tall enough to shade the southern 60' of my property all winter. There isn't often enough snow to matter, but when there is, it lasts for 2 months in the shade of the hedge, and the earth beneath that snow remains frozen. That's the southern 30-50% of my property (the width varies).

The neighbor in question has a golf course. The alternative to shade would be even more golf balls than I have now. But I fantasize that he'll go out of business and I can buy the 25' adjacent to my property and put up a mixed hedge of flowering shrubs.]

Wasn't there a thread very recently in the trees forum about this exact scenario? (I think they were even Leyland Cypress, too!).

Yes--linked below!

--JC

Here is a link that might be useful: Neighbor Tree Thread

Leylands can be a problem in many places, but they can be especially problematic around here because of pests and disease. The 1' spacing from the property line is ridiculous. It sounds like the neighbor is either very naive about the issues or is just a jerk and doesn't care...bad either way.

Unless you live in an area with an HOA, I don't know what a good solution would be in this situation. Unless the trees are damaging something on your property (which they probably aren't, yet), I don't think there is much you could do legally to get the trees removed. And, like Missingtheobvious said, pruning back hard to the property line is going to result in a serious aesthetic problem for your side.

The bagworms might be your best legal bet. I don't know if there is a way to encourage them or not (and I know that sounds horrid), but they may be on your side in the dispute. Unfortunately, as you noted, they are not going to be good for your plants.

There are a variety of less legal solutions, but they could possibly get you in trouble if the neighbor found out that you were trying to kill the trees.

I think I know how you feel, but I'm afraid there may not be a great solution. All I know to do is wish you luck!

Spray the tree and enjoy the privacy. Unless you have a very tiny lot to me it isn't a big deal. If your lot is really small what do you expect?. You will have neighbor problems on a small lot.

Or cut the tree back to the trunk to get your space back. Trees on or near lot lines are too common to involve lawyers and such.

Did you talk to the neighbor about it? He may be tired of the tree. Offer to pay to have it removed.

I would email you city/town and find out the rules (email so you have a record) and if you can cut at the property line do it

I know this thread is a couple months old but I just ran across it looking for info on Leyland Cypress.

There is much variation across the county in the laws regulating this problem so you should carefully determine the law in your jurisdiction, BUT:

Almost all areas have a law that limits the height of a fence/wall on the property line.......AND a hedge of any plant is a fence/wall in many jurisdictions.

If my neighbor did this, I could call Code Enforcement and they would make him cut it back to the property line and top it at 6'6". This might seem extreme but it does force a misbehaving property owner into coming to agreement with his neighbors. This seem mostly like a good thing, as they would only enforce this when the affected neighbor complains.

For example, one neighbor of mine has Hollywood Junipers on his side of our shared wall along 125'. He has his gardener trim them after we agree on the height. He always tells me the day they will be trimmed in case I want to be there for anything special. I like "my" side to have that twisted/tortured Hollywood Juniper look and he likes his side to be a a solid rectangle. Isn't this the way it is supposed to work?