I live in the San Francisco Bay Area in California. I bought a house in October of last year (it is now May) with an avocado tree. When I got the house, the tree was about 16' tall, very nice, shiny leaves, and a single small avocado. Around January I began to notice the leaves were lightening in color. Flowers starting appearing sometime around February or so. The tree became covered in flowers, but many leaves started turning yellow and they became sparser. Maybe 6 weeks ago I bought some avocado tree fertilizer (marked that on bag), and put down the directed amount, which seemed woefully small (less than a cup?!). I watered. I got nervous a month or so after when no improvement and put down a bit more fertilizer. The tree looks worse than ever. Still has lots of flowers but the leaves look terrible. We had a very dry early winter, with a ton of rain in March. Local nursery suggested it was getting too much water, so I have not been watering much since our wet March. I don't know what is going on or what more to do. My yard gets full sun, days have been moderate. Nothing super hot or cold. I find no evidence of bug or rot. Everything else growing in same area seems fine. What is wrong?!
Downtoearthdigs- As noted in the title, my question is about an avocado tree, not a fig tree.
You may have answered your own question with the information about 'very dry winter and a ton of rain'. Under or overwatering, ( or heavy rainfall) can cause the wilting and yellowing of leaves.
The roots of Fig Trees are close to the surface and can dry out easily.
A regular watering schedule is important for a Fig Tree.
Before fertilizing I would have your soil tested to determine the nitrogen levels.
Over fertilizing will also cause yellowing of leaves.
Scale, Mealy Bug and Spider Mites are common insects to Fig Trees. Inspect the tree carefully, especially under leaves.