Matt, stinks doesn't it?

Could be past damage or damage from too much neem, but first, did it at some point dry out too much? Have you checked the roots? Do you have that tree sitting in a very hot sunny location? Are you fertilizing often and how much? Let us know buddy.

Mike

The black spots on the leaf in the second picture looks like sooty mold.
Forms on left over honey like secretions from pests like aphid, scale
etc. If it comes of clean with a wet tissue paper then it is quite
likely sooty mold. Its presence indicates that there were some pests
like aphids before. Normally ants clean them out and at the same time
assist in spreading the eggs elsewhere. But if there are not ants at the
time of infestation then the sweet secretions of the insects turn into sooty mold.

If the spots seem translucent one possibility is damage due to neem oil. Oil based insecticides can have that effect if it is too hot or exposed to sunlight or if it is too humid. The first picture seems to have spots that are translucent - not sure from the picture.

Hi Matt,

That looks like spider mite damage and you have confirmed it. Camera has probably corrected the image a bit so it is hard to know for sure if something else is going on. Neem oil can do a lot of damage quickly if you use too much or apply when it is too hot. Outdoors a simple garden hose and mister can interrupt most insects.

Probably that deck gets a lot of sun. How hot does your deck get? Depending on the wood type, natural wood decks get 26-47F higher than ambient temperature. The wood and the ceramic are like a frying pan cooking the roots. You can buy a cheap infrared thermometer for $20. This company tested 72 different deck materials. The natural wood decks were #64-69 samples.

II think the damaged was caused by (spider mites + neem oil+ deck & pot temperature).

https://boston-decks-and-porches.com/2017/08/30/just-how-hot-will-your-deck-get/

I'd check carefully for scale as well.

Thank you all for the responses! Sorry for the delay, had a few busy days at work and it got away from me.

Mike - It's possible it may have dried out a bit. Using foliage pro with each watering. It has been very hot recently. Gets about 7-8 hours of sun/day in the current spot on the deck.

Tropicofcancer - Some of the black spots can be wiped off it appears. Almost like a fine black dust on the leaves, others seem just like part of the leaves.

Dave - I just looked it over again. I don't believe I see scale currently, though have been tricked before.

I appreciate the comments on the neem + heat. Early on there did seem to be webbing from mites, but I haven't noticed it much lately. I have to admit I probably panicked a bit and over did it with the neem, was using it every few days for a time. Temps have been frequently in the 90s, I didn't even think about it being much warmer on the deck.

I'l plan to move it to the shade to give it some time to recover and stop the neem. I worry I threw away the summer. It usually grows so well outside, in preparation for the prolonged dropping of leaves that is winter. Hopefully there's still time to catch up!

Thank you again everyone. The assistance is much appreciated!

Matt

Tropic is correct. The black, removable stuff is fungus. The dark spots are fungus or, more likely, fungus-damaged regions. Wipe the fungus off and/or use a fungicide.

It is not damage from neem oil or spider mites.

Temp of the roots = (sun radiation on pot + conduction of heat transferred from sitting on the deck + convection heat from hot air winds. Mites like dry air and mealy bugs like moist air. If you are rinsing the foliage it would have controlled the mites as soon as you went outside. With neem oil you have to follow the label carefully. I think they say 90F cut off. I think they are making an assumption that the leaf temperature and the ambient temperature are both 90F. You may have an 80F day and have a 105F leaf because it is in direct sun and that will cause leaf drop. I haven't used neem oil all summer. Probably will try it in the fall when it is cooler.

81F today. This pot is 140F. Hibiscus dropping leaves. Clearly needs to be elevated off the asphalt. Job 99 today.

Ashphalt

White clay and full shade.

Wood deck rail. Light color stain. 12:00 noon. Backyard facing North. Air temperature 82F. The deck rails has risen 46F.