So i found i have a couple of very vigorous trees.
In fruit for one plant, and in growth for another.

If i graft to them, what qualities follow the scion,
and which qualities follow the root-stock ?

I plan on grafting 2 or 3 fig varieties to this plant
but, i also want to try CHE fruit, since its in the same family.
anyone try grafting CHE to fig (or to mulberry ?)

anyone try grafting fig to mulberry ?

i just tried a mulberry to mulberry graft yesterday
and the wood split, and the center pith just fell apart.
it was 1yr wood. im guessing i might have to try older wood to graft mulberry ?

Generally speaking fruit features will come from the scion, and the vigor, root disease resistance, an wet/drought tolerance, are amended by the rootstock. 

However! It's not really that clear cut, assuming that figs will react to grafting like other fruit. There can be interactions between the rootstock that affect fruit. For example the rootstock can affect both the quality (e.g. Q-Eline reduces russetting on conference pears compared to Quince C), ripening (e.g. M27 rootstock leads to earlier fruit ripening in apple varieties), size, quantity, mineral content, and precocity of fruiting. Equally some vigorous scions will produce larger trees on dwarfing rootstock or some compact growers will still be small on semi-vigorous root stocks.

Fig-fig grafting is pretty successful, so give it a go, I'd be interested to see what you get.  I'm planning some frankenfigging myself and have been pondering which rootstock to use. I'll probably end up using whichever seems fairly tough (I'm in Yorkshire in the UK) AND is easiest to get cuttings to take, and use the scions where I struggle to get cuttings to work.

Good luck with your other grafting!

You would be best grafting CHE to Osage Orange  and staying within the species on the others

The following  details some of what you asked, some of the early posts were enthusiastic but think ultimately the others failed 

http://growingfruit.org/t/che-mulberry-osage-orange-fig-grafting/2994

greenman62 --

I'm really interested in this question too.  I gather that not much specific is known about the interactions in figs.  If you learn anything, please let the rest of us know.  Meanwhile, I plan to start experimenting in a small way myself, grafting buds of later / less vigorous / more tasty varieties onto rootstocks of earlier / more vigorous and/or less tasty varieties.  First I have to prove that I can graft successfully.  Then I have to ripen some figs on the grafts.      

For example, for buds:  I have a 1-yr old Valle Negra that is a pretty plant but not a strong grower.  It seems dwarfish (but without any obvious sign of disease).  I may graft some buds onto a very strong grower just to see what happens.  Ditto a 1-yr old JHA, which produced a couple of delicious figs but seems a mediocre grower.  This year I started some additional cuttings of JHA, Smith, Norella, and St Rita just to have a supply of buds.  

For root stock:  I have an in-ground Hardy Chicago that seems inferior in taste to other Mt Etnas, so maybe I can trade up in taste by grafting on some St Rita or Norella.  I have an extremely vigorous (and tasty) Paradiso but it is also very late; I'd never cannibalize  the whole plant but maybe I can channel some of that vigor into a variety that is a bit earlier, such as JHA.  In pots, I have some extra 1-year old cuttings of varieties that for me grew very vigorously (e.g., Black Greek, Emerald Green); and I started some extra new cuttings of early varieties (e.g., Florea, Improved Celeste).  I may convert these to something else.

At minimum, I'm hoping to upgrade flavor on some rootstocks (e.g., HC --> Norella).  I'm also hoping that the vigorous growers will impart that vigor to the weaker but tasty varieties (e.g., Paradiso --> Valle Negra).  It would be a huge and unexpected bonus if any of the earliness of Florea or IC influenced the timing of the grafted buds (e.g., IC --> JHA). 

I'm also interested in the interaction between rootstock and scion. For figs there is little information available. Ronde de Bordeaux seems like a very good rootstock to me. It's vigorous, cold hardy, prolific and early ripening. Last year I grafted a Figo Preto onto a Ronde de Bordeaux and hope to find out in a couple of years if the RDB rootstock passes some of these qualities to the FP scion. I'm also wondering if a healthy rootstock can help reducing FMV symptoms. 

I'm very curious about grafting fig onto mulberry. I believe it should work, although mulberries can be very tough to successfully graft onto from what I've heard.