I have an area where I'd like to grow an evergreen screen.
The only issue I foresee is that the location gets morning shade and only about 3-4 hours of direct sunlight (in the afternoon) in the summer, and a little less in the winter.
Is there a particular screening tree or shrub that would thrive in this amount of sunlight?
The Canadian Hemlock (Tsuga canadensis) is a very shade-tolerant tree that can supposedly be pruned into a hedge. Below is info from https://chiefrivernursery.com/canadian-hemlock-tsuga-canadensis-seedlings-transplants.html
Canadian Hemlocks are very versatile, long-lived conifers. They can live to be several hundred years old. The trees are fragrant and have small needles that are dark green on top and light green underneath. This evergreen can be pruned to any shape or height and make a thick privacy screen or living wall by planting 20 feet apart. When left alone, the trees reach for the sky and are a towering specimen reaching up to 60 feet in height. Canadian Hemlocks are not terribly drought or wind resistant so please take note of the location where you intend to plant them. These hard to find seedlings grow best in well-drained locations similar to what the firs prefer. This is one of the most shade tolerant of all conifers.
Assuming you want an evergreen screen, consider using Prunus varieties - Prunus lusitanica, the Portugal laurel, can be used for hedging or as a single shrub, needs cutting only once a year, usually in spring, to keep it in bounds or to shape, and is highly tolerant of shady conditions, see here https://www.rhs.org.uk/plants/14003/Prunus-lusitanica/Details
There's also Prunus laurocerasus but it has much larger leaves which look very unattractive if, after pruning back, any are left cut in half, they're very noticeable. There are other varieties of this plant (P. laurocerasus rotundifolia for instance) which don't have such large leaves, so they are woth considering.
Note that Prunus varieties are commonly referred to as laurel, or cherry laurel - there are other plants also referred to as 'laurel' - Aucuba japonica and Laurus nobilis (Bay laurel) so make sure you know what you're buying if the plants are not labelled correctly with their botanical names. This link https://www.laurelhedging.com/types-of-laurel-hedging/ provides an explanation of that along with a list of varieties.
If you're in the US, you might want to consider American Holly (Ilex opaca) or some of its related cultivars. American Holly actually has its own web site, with more information and a small list of cultivars. The species itself is way too large for a screen (without pruning), but I'd bet you'll be able to find a cultivar that would fit within your space requirements - check out this site for a list of related cultivars.. Because hollies takes part shade, it should meet your needs in terms of 3-4 hrs of sunlight. I've also seen American Holly growing in full shade in Virginia (and in a side note, I'm currently growing a non-evergreen native in full shade and it's thriving, even though it's not noted for liking full shade).
One important note - the American Holly species can be beset by a large number of disease and insect problems, so I'd recommend finding a cultivar that has some resistance to at least some of them.
Looking into a zone 8 forest , I see yaupon, lots of yaupon , Ilex vomitorium. A holly but no thorns on the leaves . American holly grows well here but does not make a screen- barrier- wall like yaupon. I don't know if you can buy it in a garden shop but you can dig all you want in east TX ( with permission or no one looking). You would not need to baby any that you dig up ,hardy, invasive. Red berries in winter . Deer will only eat it as a last resort. Do not make tea with it ( see name -vomitorium). You may consider interplanting with a deciduous ally , American beauty berry grows well with yaupon and makes magenta color berries . Yaupon will get to 20 feet and does not care about sun . It does want water , does great with 50" and probably does very well with 30" annual rain.
