Hi folks - thanks in advance for your advice...!

I've helped start a container garden in our city apartment building's courtyard and we are experiencing some challenges.... It is generally a shady, stone-walled courtyard with a partial canopy. A stripe of sun does move across, but it is mostly an "indirect" light area.

Some things are doing well: coleus, "candy" grass (with purple flowers), impatiens, hostas.

Others, not so well. We may have been ill-advised by our nursery sales person.

The dogwood tree came in a burlap sack around what seemed to be a clay-like ball. We were told to leave it in the burlap and plant as is. Lots of brown leaves and thinning. We did put lots of rocks in the bottom, but it seems to drain very slowly. Should we aerate? Re-transplant and loosen the root ball?

Our Japanese Maple also has some dry, curling leaf edges. Not as dire-looking, but still not as happy as we'd like...

Three Japanese Hollies are thinning and displaying very black stems and leaves as it thins out. Not sure what's going on here...

The other issues seem to be about exposure. We were sold some variagated Euonymus and salvia which probably needed full sun. I found a salvia variety that seems to be more shade-tolerant and happier....

The day-lilies also seem about ready to give up. Sad.

We are beginners in container gardening and understand there is probably just a learning curve involved in finding what works in the space, but any tips you have would be greatly appreciated!