Not my ideal plan of action, but I have little choice in the matter. Here is my predicament and my deadline is spring.

A friend of a friend has a few very old fig trees. He doesn't like figs AT ALL, and wants them gone. He has given me full reign to do whatever I'd like, as long as I take the trees down/get rid of them when I'm done.

There are some baseball thick sized trunks which I will dig up and take along with suckers and some smaller figlings.

The original trunk is over 12" thick. I wont be able to dig those up.
Based on the work entailed, and the location of them, I would rather cut it down.

I would like to keep a good rapport and my word in getting rid of them for him.

If I cut the trunks to ground level, how can I best ensure the rest of the tree would die?

Gabriel: That is a lot of work and power, thanks for sharing.

Best,
Tam

There is a product sold to kill stumps. IDK the name but you drill holes in the stump and fill the holes with the product.
  I applaud you for salvaging the trees.  I take it to heart when I see any tree killed, but fig trees are like family.

Soni

Once you have cut it down to the ground you can either rent a special machine to grind out the stump. 

Thanks.
Stum Grinding or machinery isn't an option because of space and budget.
Drilling holes seems like the way to go.

It does break my heart to kill a tree, but at least I'm continuing with other parts of it. I'm happy enough that he is letting me take what I can. Least I can do is clean up his fence line.

There is a Stump Rot ( I think that is what its called) at Home Depot.  Just like Soni said, drill holes, fill them up with the stump killer and then leave it be.  It should stop the tree from trying to grow back. 

http://www.homedepot.com/p/Spectracide-1-lb-Stump-Remover-HG-66420-4/202097353#.Ul1FsyUo58Q

I have heard that weed-killer kills freshly cut trunks and roots.
Adding some anti-freeze may help absorption too.
If the main stump is not killed, numerous suckers will sprout back next spring.

yep, i think stump killer is the way to go.  

Any plans to do a massive air layer on the main trunk?  I've wondered about using a 20 gal tub to air layer a big trunk like that versus digging up the whole tree.  Though, i'd imagine it would take a 2 to 3 years to grow enough roots to support the tree.. lol..

I've applied Roundup to fresh cut stumps before and nothing has ever grown back, though I've never used it on a fig tree stump.  But it should work the same.  Spray it on really heavy all over the cut.  Another option is to buy the concentrate and brush it on with a paint brush.  I think it does the same thing as the Stump Killer.

The best time to apply stump killer or Roundup is when the tree is actively growing.  That is when it will absorb the herbicide and be affected.  This time of year it might not do much.

Question(s):
How does the stump-killer work?
What are the active ingredients?
Does it need for the stump to be already dead and then help it rot away?

If it is in the lawn, just cut it ot the ground and apply weed killer to stump, mow weekly to kill of any suckers.  It will eventually give up.

IME, wanting a fig tree to live is the best way to kill it.  Nothing else reallly works.

Drill a hole in the stump or several, mix anti freeze with concentrated roundup, pour this in and it will kill whatever tree you want.  The anti freeze helps the round up stick inside the vascular system and ensures it will work.

Nice information, thanks for sharing.

Best,
Tam

I wish I knew about these earlier, or I would have air layered a ton of branches. Sadly, time is of the essence and I'm grateful enough for what is salvageable.

A while back; I did manage to kill an unwanted tree; 5-7" base diameter tall tree,
by pouring a whole 16 oz (concentrated all-weed-killer) RoundUp around the base trunk in spring.

It was not a fig tree.

It was just causing excess shade for my other wanted F.carica trees in my limited space.

[E: the dead 'stump' is still there; removing it, is more of a very strong muscle/effort issue.]

Not sure if a deeply rooted tree will ever give up.  For one year we have done the round up thing on suckers from (not a fig, but an aggresive grower) and new ones pop up.  It's surely a battle!

It's probably like a sweetgum ball tree.  Horrible things if you try and cut one down that isn't dead you'll end up with 100's of them popping up all over your yard.

Another option... Dig around base of the trunk. If the roots are not too deep, cut them, pull up the stump, and plant elsewhere.  If they go deeper than you are willing to dig, use a chainsaw to cut off as much the top then use a hatchet to remove the bark/cambium layers many inches below the soil line. 

Gabriel, If you havnt seen this it might be helpful. I wish there was some way to physically lend you a hand because I really beleive in what you're doing.
My daughter's name is Gabriella and she does good deeds too.  I think some angel dust comes with the name.  

This article mentions a chemical used on unwanted ficus in Hawaii that you apply immediately on the fresh stump.
 Good luck,    http://homeguides.sfgate.com/chemical-kill-ficus-roots-62378.html
Soni

Gabriel, what type of fig is it?
I can give you a hand if you can wait till the weekend.
Pm me. I have lots of space for an old stump, and the imagination
To create a 5 in 1 Frankenfig.

For me, stumps are easier to uproot if left about 3' tall. More leverage
to rock them loose.

There's also the natural way. This is done to kill lawns for reseeding.
Cut the stump to ground level, cover it with leaves, wet it really well,
then cover the whole thing with carpeting or a black plastic bag.
I've tried this method, since I have a well, and I don't want to contaminate
my drinking water.
I don't know if the stump killer is faster, but the way I've done it has killed
Maples by the end of summer, and the following spring, the stump
crumbles.

    YAYYYY  Ruuting.  That's wonderful!  I wish you good luck with the 5 in 1 FrankinFig. 

Soni, where else could we get orchard sized
fruit trees, right?
And don't think I haven't noticed that your wish list has two varieties that I possess!
;)

Very nice information, thanks for sharing.

Best,
Tam