Below are some pictures of a fig tree.

It is growing in Jersey City, NJ
tree lives in about an 18" wide slot of soil between concrete slabs.
Tree is not given any commercial fertilizer and is only watered once a week.

It was planted as a single cutting, unrooted,
just a twig from a nearby mother tree that was being cut down for construction.
The mother tree was living in-ground for over 40 years.

The twig was stuck in the ground in August _ _ _ _
No protection or care was given to it during rooting or its first year or since.

This is not my tree, belongs to a friend.
In 2012, on a couple of visits I picked at least 100 ripe figs off it each time,
probably yielded  over 600 ripe figs last season, maybe more.

Gentleman standing in front of the tree is the owner,
he is 5' 11" tall.

So, what year (or how old)  was this tree planted ?

Afterwards I will tell you the only "fertilizer" used on this tree.

Planted 2006, six years old? I've seen pretty amazing growth on in ground trees in NYC.

<Edit> Forgot to ask. What type/variety of fig?

4yrs old
Fertilized with home made mulch from grass clippings and leaves etc and anything else organic that could be used in a mulch pile.

I'll guess 5 years old.

August 2006 ?

I would tell you if those were cans of beer

2009 would be my blind guess, I have a tree that is a 4 year old with a bit thicker trunk than this one and a 6 year old that is at least half the size than this.

My guess is 4 years old.

Eight years old

I was going to guess planted Aug 2008, but then realized it was planted in Aug, so I'll guess Aug 2007.  The concrete probably helped its quick growth and I'll also guess it was fed manure tea.

It's 10 1/2 years old and the fertilizer was a yellowish liquid.

I would guess that it is 4yrs old

A yellowish liquid would have been my second guess.  My dog does wonders for my grass as long as she doesn't burn it. : )

I will have to guess home made fish fertilizer as I see there is a tackle shop next door

Jersey City is a few miles from me. My neighbor's 42 yrs old tree has about the same size of trunk, but your tree seems to receive full sunlight, I'll guess it's 10 yrs old.

I have seen 4-5 year old trees that size, and 25 year old trees that size.

I guess 6.5 years old (August 2006).  And that the fertilizer is peanut shells.  (And maybe other nut shells too).

Mike  central NY state, zone 5

my guess is 3.5 years and beer fertilizer or pepsi. 

I will guess 3 years old and the fertilizer is from the fish tank.

I say 10 to 12 years old. Since there are peanuts shelling near by, I am assuming tree was fertilized by peanuts.

15 years old, never fertilized

Let me take a wild guess... 7 years with beer for fertilizer

the suspence is killing me. how old is it

5 years old. Fertilized with beer induced urine and a handful of miracle grow a couple of times a year. Also maybe the ashes from the charcoal grill.

Look forward to the answer and have enjoyed all the guesses so far.