A dwarf japanese maple might work, but your hydrangea idea is good, too. Some dwarf rhodies (or smaller varieties) might work.

Something already trained as a standard might work to have foliage above the fence especially since fence casts complete full shade except for 2 hours. Shop at an independent nursery for suggestions. May take awhile to find what you like since that's a tough spot if full shade.

I've grown these in dappled shade spots using the reflected light from a white home, so you might try:

-ornamental grass: feather reed types

-Kerria: deciduous & can be trained up a pillar like a rose, but easier care (yellow blooming in late spring with year round green stems) Left to it's own will be a suckering sprawling shrub

-evergreen huckleberry (taller in shade than sun, slow grower)

-native salal: endures pruning to shape & grows taller in shade (doesn't transplant well from existing gardens; then you can't get rid of it once established... unless you're diligent with removing the spreading roots. I've pulled & pulled over years. Only way I removed successfully was when I excavated the entire area. Beware!)

-golden hops (research before you plant in the ground - another one to watch carefully, but when grown well is spectacular during the growing season & dormant in winter)

Great plant picks is a good site to view at link below.

Here is a link that might be useful: Calamagrostis acutiflora âKarl Foersterâ

Something already trained as a standard might work to have foliage above the fence especially since fence casts complete full shade except for 2 hours. Shop at an independent nursery for suggestions. May take awhile to find what you like since that's a tough spot if full shade.

I've grown these in dappled shade spots using the reflected light from a white home, so you might try:

-ornamental grass: feather reed types

-Kerria: deciduous & can be trained up a pillar like a rose, but easier care (yellow blooming in late spring with year round green stems) Left to it's own will be a suckering sprawling shrub

-evergreen huckleberry (taller in shade than sun, slow grower)

-native salal: endures pruning to shape & grows taller in shade (doesn't transplant well from existing gardens; then you can't get rid of it once established... unless you're diligent with removing the spreading roots. I've pulled & pulled over years. Only way I removed successfully was when I excavated the entire area. Beware!)

-golden hops (research before you plant in the ground - another one to watch carefully, but when grown well is spectacular during the growing season & dormant in winter)

Great plant picks is a good site to view at link below.

Here is a link that might be useful: Calamagrostis acutiflora âKarl Foersterâ

For small shrubs, I have a variegated pieris japonica that is just one of my favorites and it supposed to be ok in a lot if shade as long as it gets some sun. It's evergreen, and "flowers" pink in the spring, it's new growth not flowers, but so pretty. Mine has been in my yard for several years and hasn't grown all that much so a slow grower.