posted 6 years ago
My understanding is that F. racemosa is in Ficus subgenera Urostigma, which is the easiest to propagate from cuttings. The Australian Urostigma trees are often a bit more difficult though, is the provenance of your tree Australia or elsewhere?
I have never grown this species, but I have done a lot of cuttings with other Ficus spp. Ficus macrophylla columnaris is my favourite fig tree for my climate, being a true massive banyan that is well adapted to a mild temperate climate. With this species I have found cuttings are difficult inversely proportional to the amount of care you take. If you carefully take soft or semi-hardwood cuttings and propagate them in controlled environments with auxin and mist they will almost certainly die. Hack a bit off with a machete and poke it into the ground and it grows well. In Africa F. thonningii is grown by farmers by taking cuttings up to 20' long and direct placing them in situ. You'll need to experiment with cluster fig, but being Urostigma there is a good chance tall cuttings will work in situ. Better still if you can find some genetic material with existing aerial roots.
The root strength comment almost certainly refers to small seedlings vs small cutting grown plants. Obviously cuttings have more delicate roots than a seedling when young. Give it a year or two and there will be no difference. The great thing about Ficus spp is their amazing roots.