Rooting fiddleleafs, at least for me, is very difficult. At best, I achieved a 50% success rate, but more likely had a 75% failure rate, and I experimented with using different rooting media and different climates for a couple of decades to improve on that rate. I never did. I no long even try to root cuttings. Now I air-layer branches of my 25 year old "mother" plant and get mature plants that way. It is technique sensitive, takes a lot of watchful care, can take a month or more to see success, and it is still kind of hit or miss. My success rate is better though. I would try to air layer the trunk of your plant if you don't mind losing the entire plant if air-layering fails. I am only air-layering hardened branches, so if I fail to get a rooting, I just lose a branch.
If you want to try, knowing that failure means you lose the plant, go for it. If the plant is ready for the trash-heap, heck, what do you have to lose? Let me know if you want to air-layer and I will Tree-Mail you the technique I use.
P. S. I use a really expensive rooting hormone and this alone is the price of a plant. But I air-layer a dozen branches of my mother fiddleleaf each year and also root plumeria cuttings and other tropical plant cuttings, so the cost of the rooting hormone is not a problem for me. Ken
