Dear Alert:

I don't know what sort of soil you have in beautiful North Carolina, but I know you have SUN, just like ours. The lack of sun on ligustrums (we sometimes call them DISgust-rums) would seem to me to be the problem and there's nothing other than pruning tree limbs overhead or moving them to alter that. There is no substitute for sunlight.
The fact is, I've never seen ligustrums planted anywhere except in the ground. They get to be at least 15-18 ft tall and 6 ft wide in San Antonio. A shrub more suited to your site and light conditions might be a better choice.
I'd try Dwarf Yaupon Holly. Good luck!

ligustrums have to have at least 6 hours of sun to do well. Nothing else you can do can make up for the fact that they will not thrive in the shade.