There is some interesting pictures of Fig trees at Google image search.  Just go to Google image search and type in " Italian fig tree "  It amazed me just where some wild figs were growing in the old country.  One in particular was growing from old steps in Rome,  and another was growing it appeared to be out the side of a house.  Nature really makes a way doesn't it.  I may just not baby my figs so much anymore.  I thought those images were quite interesting.  Check them out.  Let me know what you think.  Ciao Maggie

Maggie
If the environment is right, the roots will find a way to grow. I have seen figs growing in the middle of high retainer walls in Asia. I have heard of some species of guava growing as weed plants in South America (& we buy a big fig size guava for $1.50 each these days). But here in Zone 5, if for whatever reason I could not get my pots inside on time by watching the weather report and the temp dips to -10C (14F), I may have to buy a new plant next spring.
(We are working hard to change the hardiness zone for our area which is considered the coldest or the second coldest capital city in the world. The bill is in the Parliament.... but is valid only for the figs).