Rock? Crushed, flagstone, etc.

What about mosses, of many different kinds. I found two different mosses on a friends concrete wall where the bushes overhang and there is no sun. I also found what looks like to be a succulant of some sort. Don't worry, I only took a little and left the rest to grow) When I can, I'll post a picture of it. Well anyway, I put them on a conctrete brick, part of the "succulant" on top of the moss where I had found it growing. The brick is in an area under a birdbath where it gets very little light. Musrooms like it wet and dark. I use to see beautiful multicolor, multishaped mushrooms, on moss, under a rhodadendrum (sp).

I wonder how impatients would do? They love the shade too. Certain ferns might work as well. Maybe almost anything from a terrarium, would work. Assuming the area stays moist.

Make a little scene, with sheet moss cut to fit the area, little branches for trees, a bowl of water might attract some toads. Pretty bright rocks to bring light.

Paint a pot or rocks with yogurt or sour milk.Blend the yogurt/milk with a piece of moss, then paint it on. Keep it moist with a spray bottle, and it will grow moss.

Susan

Thank you, all will be considered, impatience - nice idea.
Also love the idea of attracting a toad, but I do not think I could give the amphibian a decent environment..

You could also try a hosta called lancifolia. I have some growing under the edge of my back porch. It there's enough light for weeds it should be fine.

mint if you dont fear it ~smile~
I like lemon balm. water if it doesnt get any rain or runoff. shear it when it gets leggy and it will thicken up and fill the space.

smells good when you sit on the step and makes a nice garnish for drinks and fruit cups

jc

Vinca Minor, a small, evergreen periwinkle, grows quickly and is lush in deep shade and clay soil in my neighborhood and around my house.

A yellow, creeping lysmachia called Creeping Yellow Jenny apparently grows either in sun or shade in clay soil. I have in both and in both dry and wet areas. Anyone I've given cuttings to says it thrives in any setting they put it. It turns a nice red copper in the fall, stays semi evergreen in winter and returns a pretty chartreuse again in early spring.

Corsican mint is an evergreen for me in my clay soil and doesn't seem choosy about whether it's in sun or shade. It's very short and green and shows up the smaller, light colored garden statues because of it's leaf proportion.

Once all these got started for me, I have to keep them at bay.

Bishops Weed does well in shade, though some people consider it to be a weed. Maybe corral bells? They can take shade. I also recommend a shrub called snowberry. It is one of the few shrubs that grow in shade. It has cool white berries for winter interest, too. And how about a yew? Because of the West's bright sunshine, I can only grow yews in full shade. My disclaimer: I've never gardened in PA, so my suggestions are based on Intermountain West gardening.

Maybe I don't understand the place you are talking about, but what about buying lattice to cover the area with a screen and then grow a climber on it? That way you can also use the area under the steps for storage - maybe that's just a concern in NYC where every inch counts.