Don't waste your money, i have superthrive and had no luck using on anything except orchids... Unfortunately it does sound like your tree is dead =/ but keep the faith and treat it like it's alive, maybe it'll pop back.

I once bought a giant banyan ficus, beautiful and on sale from a couple hundred to 20 bucks bc no one wanted it and the garden was basically throwing it out. But it was grown for topiary and had a long trunk so i made a trunk chop just hoping that it would have a lot of saved up energy! But no such luck, the tree never popped back... In fact every single person i know who has lost leaves or defoliated ficus has lost the tree...

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