If it's just morning sun or not more then 4 to 5 hours of sun on that area you could plant a weeping Japanese maple.* Be very careful when you select one as they tend to grow wider then tall, especially if it's a low graft tree.* The lilac will need 6 hours of sun or more to bloom well.*
I also want to correct something I posted earlier.* It's HARRY Lauder's Walking Stick, not Henry. *:?* I'll edit my post, but I want to be sure you have the correct name.** Glad I gave you the botanical name.* :)* That can take full to part sun.
Newt
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.