i dont understand the pic at all .. it looks like a potted plant.. out of its pot.. sitting on top of soil ..

i am not concerned.. about white stuff.. braking down the organics in your soil ... and i dont see any on the bush ...

if you figure out a way to kill a F.. let me know .. you could.. right now.. cut it to the ground for winter.. and it will be back by next summer ...

i dont know why you had a bunch of dead branches in it.. and i suspect.. you pulled them out.. before you thought of snapping a pic... eh???

there is no need to treat it.. in any manner ...

ken

I cannot determine what you call "white fungus" and spots of overexposed sunlight on the plant. Shade the plant and use a flash to show the fungus better. You might even use a Paint program to draw arrows and circles to show what you want us to see.

Is the "fungus" on dead wood? Just chop it out.

How is the plant generally? Good leaves? Does it bloom?

Do you trim it? Is it a large mass or trimmed into a ball (yuck for both...)

I chop mine to 12" high right after it blooms and it sends up great sprays of branches for next year. The base gets good cleansing sunlight every year and a lot of air flow. Pull out anything dead even old root stems.

The plant in the pic is 45 years old.