The fiddleleaf ficus resists all efforts to root. They are completely different than the F. Benjamina. Commercial growers simply won't propagate the fiddleleaf, knowing that their success rate will be 25-50%. That's the reason one seldom if ever sees the fiddleleaf sold at big-box stores. No commercial grower could stay in business long if his success rate was between 25 and 50%. I have now found a source for "baby" fiddleleafs, grown from seed. I have searched for over a year to find this plant grown from seed. After talking to a grower in Australia who occasionally has seeds, I now know why plants grown from seed are hard to find. To flower, the fiddleleaf has to be mature and large. I am talking about 20 yrs old and 40 ft tall. They will then flower. I personally have never seen a fiddleleaf in flower, but then, I have never been to Australia or Africa. The flowers last a brief time, often only a day or a night. The kicker is that the flower must be pollinated by a specific wasp, a wasp native to small parts of Africa and Australia. The wasp apparently is found no where else on earth. Anyway, try your hand at rooting cuttings or air-layering. You might get lucky! I will probably now sell the seedlings, with 4-7" leaves, rather than spending all the time and effort trying to get larger plants from cutting/air-layering my "mother" fiddleleaf. I expect the seedlings to grow 6-12" this year and 1-2' per year thereafter.
I don't think the plumeria can be air-layered. At least I have never heard of anyone doing it. They can be grafted but I have never tried to do that. Hetty knows far more than I about grafting plumeria. I propagate my plumeria by taking nice, plump cuttings, approximately 6-12" from the tips of branches. I allow the cut ends to callous for a day or even several days and then I pot them up, either singly in 4" pots or tied together in a bundle and in 6-8" pots. People have very different opinions on what is the best rooting medium. Some like 100% perlite, some simply use whatever potting soil is at hand, and some (like me) make up their own mix. I use 2 parts coarse perlite, 1 part (non-fertilized) potting soil, and 1 part fine horticultural charcoal. I dip the bottom inch or two in rooting hormone, make ahole in the potting medium, put the "treated" cutting about 3" deep, and firm up the potting medium around the cutting(s). I also re-wet the potting medium before putting the cutting(s) in and then keep the medium just moist, watering when the top 1/2" looks dry. I keep the cutting(s) in a shady area but an area with good air movement.
P. S. The "whiter" the flower, the easier it is to root. My 'Celadine' will root in 2-4 wks, whereas my Scott Pratt (dark-crimson flowers) takes 4-8 wks, if it roots at all. Good luck.
