The weather here in northeastern PA where I live has been what I call pretty
good. I has rained about nce a week approximately 0.5 inches per week. I

Spider mites do best on stressed plants in low humidity. Most crops need
about 1" of water a week, so you may also be underwatering, as "watering when
the plants start to droop" is likely a bit late, and usually too little
(it takes a long time to get half an inch of water on a plant, by standing
there with the hose -- also longer than most people think with a sprinkler.)

Tree problems can be harder to diagnose than annual problems, just because
trees take so long to die, and conditions they experienced 5-10 years ago
can play into their current condition. Annuals and plants grown as annuals
are much easier.

Kay