Oyster shell mulch
Fig trees on Ocracoke barrier island, N.C.
Just an overgrown sand dune base and salt spray, but the local families have been growing figs since the 1700's.
Last summer, one lady "put up" 428 pounds of figs and made lots of fig cakes.
In December 09,"root cuttings" , one of our Forum members had a thread about Nematodes and lime/oyster shells.
On the island, the fig trees are heavily mulched with oyster and clam shells.
Considering sandy soil and nematodes , then seeing many 8 ft. trees , there must be some truth in using oyster shells / limestone as a preventative.
Plus, they must help keep roots from freezing.
I do not know, but the trees are growing and producing figs, in most every yard. So, I am going to the docks and get some shucked shells for my new trees. Fred