I'm in NY and its been hot, any sunny day watering daily virtually anything in a pot and I have many, went from rain rain rain to the 90's

So it was drought stress. But I don't understand what those yellowing mean on those leaves. I thought they would indicate some sort of nutrient deficiency, not drought stress. And I thought citrus like to completely dry out before getting watered again?

When it is hot out, plants transpire (lose) water at a higher rate than they can take up into the roots and the leaves curl or wilt, so watering does not help if the soil is already damp. The signs you describe may be root rot, which is often brought about by over watering.

When it's that hot, I keep mine in part sun to let them cool and rink. Vladimir made great points, the same with my trees.

Mike

I d say the leaves are old I see no new growth and you got fruit

I moved all my mandarins to morning sun only BTW

Actually most of those leaves are fresh new growth from Late May-Early June and some of them are starting to turn yellow. But the yellow ranges from veining yellow, yellow on only the edges of the leaves.

I also know that any plant stops photosynthesizing in temps above 90 degrees F, even for the sunniest plants but how about citrus in tropical areas like Florida heat and Japan heat? How are they stressing over NJ heat when they could take actual tropical heat like a champ? Japan has summers that go well over 100F for weeks/months in a row with intense humidity you can never imagine in NJ and yuzus and mandarins in the ground shrug it off like its nothing. I'm sure citrus nurseries in Florida don't move all their citruses in part shade on sunny hot days. I hope it's not rot. Is that reversible once it occurs? I have only been watering it about every 2 weeks when I'm sure that it has completely dried out.

just liquid fertilize and don't panic, with all this rain nothing is accustomed to this yet either......we had fast summer

BTW in the evening after you liquid fertilize things are taken up.......

I actually have been putting them under an overhang everytime it rains if the media was still moist. I don't let rain hit an already moist media on my citrus.

I use foliage pro dynagro for every watering.

But you have 5-1-1 it can pour on your citrus and rainwater is good

Don't think that a tree will not get root rot in 5-1-1 when it rains often. I speak from experience.