Discolored leaves on my crepe myrtle

[SFDrake]

These are crepe myrtles that I got from the Arbor Day tree giveaway. When I got them they had been in the mailbox for a couple days unbeknownst to me, so I put them all in a nursery pot with some organic soil and have been watering the heck out of them since then. They've been doing great until a few days ago I noticed Leaf discoloration. I believe it's due to overwatering, but I want to see if anybody has any experience with anything else with their crepe myrtles that looks like this. I ordered a water pH test kit to check my tap water, I am having similar issues with my Satsuki Azalea that I believe I also overwatered. I sprayed the crape myrtles down a week ago as I noticed some aphids on the back of the leaves but I didn't see any today . any help would be greatly appreciated

 

[rockm]

Not unusual. Interior leaves will drop off because they’re shaded out by extension growth. Cut this long extensions back and you will get new tighter interior foliage