Texas Ebony being strange

[PastryBaker]

I have two Texas Ebonys from the same nursery. And they have been doing great. All the sudden one has yellowing leaves. They both get the same light outdoors.
I did have to put up a light shade last week when we had a heat wave.
The water PH is 6.4-6.6. I water them when they are just starting to dry.
The only difference it the one with the yellowing is in a little different soil. The one that is not yellowing is in an inorganic mix and the yellowing one is in an inorganic mix with a little bark in it. They both came in those mixes.
I am not sure if it is leaf burn, overwatering or underwatering. When I check the one that is yellowing for watering, I will stick my finger down halfway in the pot and it will be dry, but as I go further down it is moist at the bottom. So I don't water. They both have lots of drainage holes.

I know it is a few yellowing leaves and I can be over reacting.
Which I don't do with my orchids. When they have a yellowing, I don't worry...lol

Thanks and Happy Sunday.

 

[Wires_Guy_wires]

When I have this happen it's usually because I didn't chopstick the soil for half an hour after repotting. Soil pockets can lead to weird differences in moisture levels.

The bark can play a part too, as it can take up some nutrients and temporarily keep them locked in. Once it breaks down, that's all released again.

 

[PastryBaker]

When I have this happen it's usually because I didn't chopstick the soil for half an hour after repotting. Soil pockets can lead to weird differences in moisture levels.

The bark can play a part too, as it can take up some nutrients and temporarily keep them locked in. Once it breaks down, that's all released again.

I was thinking it is the bark. Because the other that is potted in 100% inorganic is doing great.

 

[Wires_Guy_wires]

I agree with your line of thought. Upon closer inspection it seems that the oldest of the leaves go yellow first, a sign of root issues or nitrogen deficiency.
Since the rest of the plant, apart from those older leaves, show no ill signs, I'm voting in favor of a nitrogen deficiency.

If you up the feeding schedule, those yellow leaves don't magically disappear but the issue will stop expanding onto younger foliage.

 

[PastryBaker]

I agree with your line of thought. Upon closer inspection it seems that the oldest of the leaves go yellow first, a sign of root issues or nitrogen deficiency.
Since the rest of the plant, apart from those older leaves, show no ill signs, I'm voting in favor of a nitrogen deficiency.

If you up the feeding schedule, those yellow leaves don't magically disappear but the issue will stop expanding onto younger foliage.

Thank you. I will do that. I was inspecting it today and even though there are yellowing leaves, there is also lots of new growth and leaves.