Q.Is There A Way To Get Grass To Grow Under Trees?
Very large holly tree in next doors garden which seems to stop grass from growing our side on the fence, so there’s a big bald patch in the lawn… tried lots of grass seed, feed, and ariating the area, but with no luck

Certified GKH Gardening Expert
If the tree was in your yard I would suggest mulch, which is the best thing to put under a tree. But since it is next door, that won't help you.
I'm guessing you tried shade grass. If the patch is right next to a fence, did you consider a shade garden? If that isn't feasible you could try mixing in some groundcover in the bald patch. You also could lay decorative rocks in the area and add some containers with shade flowers.
Here is more:
https://www.gardeningknowhow.com/ornamental/trees/tgen/tips-for-growing-grass-under-a-tree.htm
https://www.gardeningknowhow.com/special/shade/ground-covers-for-shade.htm
https://www.gardeningknowhow.com/special/shade/discovering-the-benefits-of-shade-gardening.htm
https://www.gardeningknowhow.com/special/shade/perennial-plants-for-shade-gardens.htm
https://www.gardeningknowhow.com/special/shade/shade-plants-that-attract-hummingbirds.htm
https://www.gardeningknowhow.com/special/shade/evergreens-for-shade.htm