I like this organic design feature because you have the flexibility in opening up ( via pruning ) the canopy of overhead branches to let in as much or as little light as you desire.
It is also quite appealing to watch the native fauna jumping and flying from branch to branch as a light wind rustles the branches back and forth above your head.
Below is a photo showing a bosque of Swan Hill Fruitless Olive trees in Marin County CA forming a natural pergola that overlooks a formal rose garden.
|From Loropetalum chinese|
This photo was taken about 9 to 12 months after we finished the installation.