The green grass with drain and then up the hill is ours. The knockout roses are on the neighbor's property to the left. This pic is from 4 years ago and they hadn't planted the vinca yet. The vinca is doing fine, by the way, and entering our yard. The problem is that there is run-off from our yard into theirs and what they really need to plant are some shrubs, not flowers and vines. The roses they hate so much are helping them but they don't realize it. The hillside above our 2 backyards belongs to the houses above us--but those neighbors wouldn't plant anything to avoid erosion and run-off so we both had to spend a lot of money planting that hill. We used to be joined by a common...annoyance...of the neighbors up above. But now we are an annoyance to them too. I like Indian Hawthorn but have only seem them about 2-3 feet high. Didn't know they got any taller than that. I'll look into them...

tj,Sorry I wasn't clearer about type of shade. Although this is not deep, dark shade; it also could not be classified as dappled or partial shade. I would call it bright open shade. The source of the shade is our neighbor's locust trees. The area gets 0 hours of direct sunlight, and perhaps 2-3 of dappled light, but has the advantage of a southwest exposure which brightens it up a bit. Having had very heavy shade in the past, I am pretty familiar with shade plants, and I feel sure the trees I mentioned would grow there, with the exception of the chokecherry which probably wouldn't be happy there. Though some non-shade plants might grow there, I don't think they would thrive in this location. If you have other ideas of trees and/or shrubs which would tolerate bright shade, survive our temperature extremes and clay, and do a good job of providing screening I'm open to other ideas. The area we want to screen is a strip about 25' long and varies in width from about 10' to 5' from end to end.

Leyland cypress are beautiful, but they get HUGE (can be 15 feet wide and 60 feet tall), and they are bagworm magnets, at least here. They grow so fast that they'd work you to death trying to keep them pruned any smaller. Not to mention the fact that you'd need a cherry picker to do it. If you want a conifer look, I'd suggest Arborvitae, Emerald (or Emerald Green), also called "Smargd". It is 10 to 15 feet tall, but narrow, about 3 feet, and absolutely carefree. It will grow in any light exposure from full sun to full shade (I have them in all). You could also go with hollies. Burfordii is nice and the size you want. It has beautiful form and color, and the berries are a nice bonus. Foster Holly would be another possibility. Some other possibilities are Banana Shrub (Michelia figo), Camellias, Gardenias (they won't like competition from other trees), Ligustrum, and Cleyera (one of my personal favorites for hedging).

Along with a photo, an indication of where you are is necessary if you are to get useful suggestions since what grows in FL is quite different from NV or here in NH. Here's how to add it to your profile so that it posts automatically by your name when you post so that we don't have to ask. Go to Your Houzz in upper right of every page, click Edit Profile, and on the left side click advanced settings. Well down the advanced settings page is a blank labeled Climate Zone for Garden Forums along with a link to find your zone. If you add info on your state or the nearest large city you will get even better information since zone only relates to average coldest winter temperatures. Then return to the top of the page and click Done Editing.