We have two very beloved trees- an Adriatic and a Black mission - both in pots. Kept in full sun. Recently been showing yellowing leaves that eventually fall off, with some black spotting. A few leaves also show white scale, which doesn't wash off. Tree is producing some fruit budding, but I'm very concerned! I soak these every two days, and use Tappin Roots fertilizer ever two weeks. We live in zone 9b. Any ideas what we're doing wrong?! Very concerned Very greatful for any advice