9 yr old fig tree
We have a 9 yr old fig tree which produces an abundance of fruit each year, but some of yield never ripens. It is totally in a SW sun position and is a very hot area of the yard. We have mulch underneath the tree nearing the rim of the canopy and then rock is around that. We water w/underground sprinklers and when it gets to 105 degrees or higher, we water the ground around with hose water 2x a week. Last winter we had to cut the center top and two other branches due to cracking of the wood. We also have painted the tree with diluted latex white paint. The tree has developed leaves that spot, yellow, dry up and drop to a crisp. Now this year there an abundance of figs, but they are not edible. They cluster at the end of the branches with barely any leaves since this leaf situation is happening. The smaller figs turn hard, like shelled nuts, and the larger figs look beautiful and then turn spongy with a rusty bottom. We are so sad and want to help this ailing fig tree. It's struggling to survive and we need to come to its aid. Is there hope here? Please advise.
The leaves dropping sounds like a fungus. Because of the stress from the fungus, the plant is aborting young fruit and cannot keep up the energy for supporting the older fruit. Start the tree on a fungicide treatment schedule - every 2-3 weeks treat the tree with a fungicide for the rest of the summer. Make sure to clean up and dispose of any fallen leaves. While the tree is trying to recover, I would recommend removing the fruit. The quality will be low anyway and the removal of the fruit will allow the tree to focus energy on recovery.
As for the fruit not always ripening, fig trees slow down their ripening when they are stressed. Check to make sure that the tree is getting enough nutrients and water and this should help it produce more and better fruit in the future.