Michelle,
Sorry no one has answered you until now. I just saw your post and wondered how your trees are doing? As you say you are new to organic gardening, I wondered if you'd been using weed & feed products in the years past? By now, you have probably learned that these types of products slowly kill your trees, causing them to evidence more and more symptoms as time goes on. They die slowly over years. Storm damage has the same effect sometimes, causing enough to sicken the tree and expose it to disease but not outright kill it quickly.
That said, I would ask if you applied the sick tree treatment? I have had great success with a very old ( 60+ years) Texas ash tree and a very sick (when I moved into my new home) pecan tree. Both were revived from years of weed & feed abuse, neglect and a variety of useless and damaging "treatments". Applications of molasses and cornmeal have helped to revive the life of the soil around them and allowed them to utilize the nutrition in the soil to rebuild their systems. Both were old enough that root flare wasn't a problem but I have lost other younger trees to this insidious killer. Compost in liquid tea or solid form at about 1/2" does a lot in a little time.
Good luck, I hope I'm in time to help and please let us know how your trees are faring. We can't afford to lose even one!
Kathe