David:

You are right, most here couldn't kill a fig. But I once lived near the worthless wild kind and I'm not a fig lover unless they're dried! Anyway, I'd try a very heavy dose of Roundup applied to the foliage when the tree is growing rapidly. After the leaves fall off, cut the top down. Wait if you can to see if the tree sprouts back from the ground. If so wait until it gets a foot or two tall and spray again. That will likely do the trick. If there is no sensitive vegetation nearby, adding some 2,4D to the Roundup would help.

The Fruitnut

FIRST THE DA VINCI CODE, NOW THIS... IS NOTHING SACRED ANYMORE???

LOL. I would think you could use a shovel and cut a 18-24 inch(60cm if my math is correct) diameter ring around the tree about 12-16 inches (40cm) deep, and pull it out while beating the soil off the roots to fill your hole. I've begun digging a tree out of the ground to move back into a pot, so I'm taking more of the root mass with it, but I am using this method.

~james

Yeah, I asked this question last year when a bird planted a tree in an inconvenient spot in the backyard - the fruit is huge, dry and insipid though. After all the shrieks and fainting, someone recommended wrapping tightly some wire around the trunk or remove the bark and cambium all the way around.