I can attest to the aggressive runners and thicket-forming tendency of flowering quince, my neighbor has one along our shared property line and every year I pull up about a hundred shoots all across that corner of my yard, sometimes 10+ feet away from their bush.
I would only recommend it if you plan to mow on both sides of it to keep it from spreading too much.
Interesting! My parent’s quince bushes never showed signs of running to that degree.
This one also never sets any fruit, but has gorgeous red flowers early in the spring, so they are probably different cultivars, maybe some are more prone to spreading that way than others.
Disagree on this one. Let’s say he plants a row readily available maple saplings there a ton of them in the wooded part of his land. In 5 years they will be my problem with their branches spreading south. If I plant something I can use or enjoy and make the neighbour happy, I can avoid such problem.
Have you thought about mountain laurel or cherry laurel.? Not edible but they make some great evergreen privacy hedges around here.
My kiwi vines are doing their best to tug o war with a cottonwood grove on the edge of my property. My neighbors don’t care but boy can they grow. As many pointed out. Like grape vine on steroids.
Raspberries could work too. If you left the canes taller towards winter. I know I cannot see thru mine when it’s dormant. The shade may reduce the fruit, it also may increase the lanky growth. But still easy enough to keep under control.
The raspberries is an interesting idea, I am just not sure if they grow tall enough in partial shade.
You may very well be right about the different varieties/cultivars. My parent’s quince was an older bush of a type quite common in our area, with smaller blossoms than some of the newer varieties (but still quite pretty).
In spite of being in shaded by pine trees, it produced a decent amount of fruit, which was yellow-green, very hard, and slightly smaller than a baseball. In fact, I used to use them for batting practice and they would shatter in a very satisfying way if you made good contact.
I didn’t know they were edible at the time, but I’ve read that you can cook with them and some people say they can be tasty that way. (Anyone here ever tried?)
Yep, the jam is wonderful, you also can use it as stuffing for poultry, especially for duck or goose. You can make sour-sweet sauce for meat from it. I also like them as a fragrance.
Whatever cover they offer disappears during the winter. I could take a picture of my raspberry hedge so you can see (through) them as they stand now.
Again; I am a big fan of keeping happy neighbors but if he truly cares for privacy he has his own land to do whatever pleases him. It would suck for you to go through the hassle and him still ending up unhappy about it.
This screen is probably mostly for myself. Just imaging, you get tied of bending position in the garden and straiten yourself for few minutes, take your eyes up and and … look into your neighbor window 
I want to stop my eyes on something else other than their windows or bare pine trunks 
That simplify things! Then there is no concern about the winter, you are not going to be doing a lot of bending then 
Oh yes, I will!!! 
The warm winter like this one gives opportunities to get ready. I was digging new beds this weekend believe or not!
ive read that some people grow trailing blackberries by allowing the old canes to die on their own and the new ones grow on top of the old ones and pile up over time. no trellising. ive also read blackberries are more shade tolerant than raspberries esp. trailing varieties. maybe a wall of blackberries is what you need. thornless of course or if you want a true barrier grow thorned.
I have a couple in zone 5b for privacy. They grow fast. If you dont prune they get really dense, work year round as a screen. My male vines kept getting eaten by the dog so never got fruit, but they flower most years.
I hear you there, I’ve spent the whole winter except about a week where there was snow on the ground digging beds for new trees and landscaping. Most of that time I’ve been in shorts and many days with no shirt the winter has been so mild.
I’m considering doing the same type of privacy screen around my BBQ pit area. I’m leaning towards grapes, but I never seem to have any luck with grapes and they end up dying. I’m not fond of kiwi, so I’m not sure what to do. In my case the area is not shielded too much of the day from the sun.
Deer also love kiwi vines.
Well then kiwi is definitely out for me, (unless I dig a pit in front with wooden stakes below to turn them into shishkebabs).
This is the male hardy kiwi vines that I had growing on my fence. This is two plants, including a male arctic kiwi (white tipped leaves). They were in part sun/part shade and were monsters. The roots did not sucker and it never got out of control that way, but the vines would travel 8-16 feet, at least, down the fence (and out). The females that were in a more shady location were better behaved. I made the awful decision of putting up a shadow box fence instead of solid fence and this did screen the neighbors. It did nothing for the noise and screaming parties. I was zone 6b at this house.
I don’t know if common laurel or Portuguese laurel is hardy in your area, but I’ve heard they can take some decent cold. They are very common as a hedge here on the west coast, even all the way up into southern British Columbia. I think it’s stunning with the glossy green leaves, and particularly pretty after a rain when the sun strikes. Also evergreen clematis does well in fairly cold areas. I don’t think you’ll have much luck finding a fruiting plant that is evergreen in your zone. I know people grow maypop passion vines as far north as Pennsylvania, but even those are deciduous in colder zones. Hardy kiwi are not so great for privacy in the winter months.
I think I selected my privacy plant for shade. It is Kerria japonica ‘Pleniflora’
and Kerria japonica ‘Golden Guinea’
Not a fruit, but blooms in full shade and doesn’t like the sun much, so it is not going to travel to my side, grows fast to 5-6’, but doesn’t spread uncontrollable, have enough of the branches to create a light winter screen, have the branches green in winter, hardy to -20F. If let to be wild may spread and work as erosion control (I need that near the creek that crosses my property) .
If all that info is true - great plant for my purpose.
