Did you use the neem oil in direct sun? I think when you use neem it needs to be done in the evening out of direct sunlight.

No, I did take care to spray in the evenings...

Oh, no! Not seabird guano! You should have used hummingbird puke!

It is much less likely to cause discoloration on the bottom of the leaves!

Pahahaha! Hummingbird puke, that's hilarious...

The plant looks pretty healthy over all, but the leaves do look pretty dark. How often do you water it? Have you tried a Ph test? Anybody out there that knows more than I do??

Kim

Note how the discoloration is focused around the leaf veins and the edges and leaf tips? That's circulatory damage and the most likely cause is excess nutrient damage.

Skim off what you can from the soil surface, flush through the containers with water, and monitor. You will likely lose those leaves but the new growth should be ok.

Next time go much easier on the supplements - even organic supplements can easily burn plants - especially container plants and all that excess nitrogen will only get you big bushy plants with minimal production anyway.

Dave