What can I grow by this south east facing wall

I have a 100 feet south facing wall with poor soil (I don't know exactly how poor, but there was most likely "filler" soil added when it was built, and it's rich enough for grass to grow, but you can tell it doesn't grow particularly well). Building is 50 feet wide and it has no gutter, so when it rains, it gets lots of water on its sides, but it drains well enough.
I put some plastic mulch so that when I decide what to grow, the soil will be ready.

I want a cold hardy (zone 4) perennial that would ideally thrive in those conditions (i.e. I don't want to put tons of compost or have to weed it for years). Bonus points if they're edible, but ornamental plants are OK too.

It's a weird spot where it's basically full sun in the morning till noon, and nearly full shade thereafter. So I don't know what to make of that.

I think you will not get around and help the soil to get better. If you want to keep it really low on work, you could sow green manure and let it grow, then mix it under with the top layer of the soil. This you can do a few times.

Other than that, the wall looks like a perfect wall for training fruit trees like apple, pears or even vines like grapes or similar. Especially peaches like the small roof to not get soaking wet when it rains. I suggest you just pick up what you like most and try to grow it there and see how it goes and then later extend to whatever works.

The thing is, I have plenty of space that is better suited to, say, apple trees (full sun, better soil). Also, I wasn't particularly clear in my post, but I just want to cover the 3 or 4 feet that's covered by the plastic mulch.

Jerome Lee wrote:The thing is, I have plenty of space that is better suited to, say, apple trees (full sun, better soil). Also, I wasn't particularly clear in my post, but I just want to cover the 3 or 4 feet that's covered by the plastic mulch.

The space from the image would be enough for trees, if you train them on the wall. I was thinking about something like a fruit wall [1].

Another idea: You could put (rasp/black/tay)berries there or similar. They basically grow like a weed, are very hardy and don't need much from my experience.

[1] https://www.lowtechmagazine.com/2015/12/fruit-walls-urban-farming.html

You have received so good ides for planting.  Have you considered using part of that south facing space for a simple lean-to greenhouse? Even without heat, it could add a month or two to your growing season.

Maybe I'm crazy, but this doesn't look like a south-facing wall.  If you are wanting to plant in the area you are solarizing, then it looks like an east-facing wall.  I believe south-facing walls as far north as Quebec should get sun all day, unless blocked by something else, like trees or another structure.

I would also consider hardy berries.  They could probably handle the poor soil, and also the runoff from the roof (which looks pretty high, so might hurt more delicate plants).

Although that space gets shade, the white building opposite may be reflecting some light, even if not direct sun. I think there would be a number of berry plants that would be happy there.

What time of day was the photo taken?

Are you prepared to build some sort of trellis or several along the wall? Plants would help to break the wind in winter, but with a metal roof, will snow come sliding down and crush everything there?

That looks like an East facing wall to me and sounds like it from the description.  Once the OP clarifies, we can edit the title of the thread.

I'd say currants, gooseberries and hazelnuts would do well in part sun in zone 4.  I've heard seaberry and wild plum can handle part shade as well (from Edible Acres youtube channel in upstate NY)

Thanks for the replies so far. It is indeed less south facing than I thought it was, but here's a picture from google maps (top is north).

Snow coming down the roof is an interesting consideration. A trellis is definitely an option, at least for part of the wall.

Jerome Lee wrote:Snow coming down the roof is an interesting consideration. A trellis is definitely an option, at least for part of the wall.

Falling chunks of snow could break branches on things below, but there would be ways to fix the problem - you just want to know so that you take it into your plans.

One way is metal bits added to the roof that encourages the snow to melt rather than come down in big chunks, however that can increase the snow load on the roof if the intent had been that it would slide off.

A second way is to build a sturdy trellis in such a way that metal roofing or similar could be leaned against it at an angle in the winter to deflect any falling chunks of snow. This way the pile of snow would be further out from the base of the building's wall, which may not be a bad thing from the perspective of flooding - win/win - stacking functions - what permaculture's all about!

I'd definitely vote for currants.  I have some in a pretty shady spot where they see avalanches of heavy snow off a metal roof.  When they emerged from the snow pile this spring they popped right up and have fruit on them now.