Tiny arachnids might be the cause of these bumps, blisters, and curls. Ordinary spider mites can be the source of this sort of damage as can an even tinier Eriophyid mite. We say that spider mites are nearly impossible to see with the naked eye....but the eriophyids are even smaller!

Inspect, with a magnifying lens, the inside surface of the folds and blisters. Better, take some leaf samples to your local extension office. They should have a microscope there. You can see the tiniest mites with a simple dissecting microscope.

That's new to me. I'll send the sample to my local office for info.

Thanks,

Johnny

Johnny:

Please come back and let us know what you find out? I would love to know. Mine did that at one time too and I could never understand what happened to it.

Thank you.

Hi Meyermike,

Sure, no problem.

Johnny

I was told there was no sign of microscopic mites or scales. It was caused by leaf miner.

I'm going to put the plant into the ground in a week or two. Hopefully, the cold weather will cure the problem.

Thanks,

Johnny

That theory is a lot more credible than leaf miners, which I see no evidence of in those images.

That was what I thought. I don't see any trail of leaf miners. I've two identical blood orange plants in a five gallon container. Both are 5 ft apart. Both have leaf curl issue, but one is minor. The minor leaf curl plant has a trails of leaf miner. The photo I posted above doesn't has the trails or sign of leaf miner.

The good thing is both survive and not a big issue. Next week, I am going to plant both to the ground. It will be 50 feet apart and at different places. I will keep an eye on both plants.

Thanks for your help.

Johnny

My experience with my garden citrus is that when I see this symptom, it most commonly is the result of over fertilizing... not to worry, it will grow out of it.
Spider mites and aphids can cause the same symptom, but in the case of aphids, in my experience, it usually follows over fertilization... as in maybe the new growth is extra sweet?

Now for some reason, I believe Jean.

I have never seen Aphids on mine and you would have to be blind as a bat to not see them before that kind of damage is done.
As for Spider Mites, not that either, because the leaves would be cupped and absolutely not that green, but a bit dull in appearance and drained of life if anything, not to say severe leaf drop.

Jean:

If it is a watering issue, how does this happen? Could it be in between unwatering and overwatering practices?
Uneven watering as in one part of the soil gets wetter than another? A fast drop in temperature before the tree can drink? I am lost on this one.

Thank you

Mike

Yep, this is the same result i saw after heavily fertilizing last year.The new leaves came out really quickly, large and round, not so long and thin as normal, and then were wavy, curled and knurled like that. Pulled thru fine though with regular watering thruought the season.