I see you are in zone 10. If you are sure you didn't over-water (like something major happened) then Yes, it could be the exact problem you are talking about with soil moisture: un-even water distribution. I have several trees in the type of mix you appear to use and this is the #1 reason I hate it. In our hot weather we're taught to not water until the top few inches of the soil is dry. Well guess what, over time this will develop dry patches that will never become re-hydrated pending constant rain or major intervention. I fought this problem two weeks ago with 3 of my container citrus trees in bagged mixes. I could feel the soil had dried out from winter and I was preparing them for Spring (the trees looked fine BTW). Having experience with this, I was DETERMINED to wet 100% of the soil using whatever method I could. I watered it for the entire DAY -- and the soil below 3 inches was still dry. I watered until it was soaked, went away for 30 minutes, came back and did it again: repeat many times. The next day I submerged it in a container filled with water and walked away for 4 hours. Came back and pulled it out -- still dry inside! This is why I hate peat and bagged soil mixes in a desert climate. If you are trying NOT to over-water and mistakenly wait a little bit too long, you've created a dry patch. The patch will only get bigger the more often you make those little mistakes. If this is the case with your tree, submerge it in water and use any type of dowel (smooth skinny stick) to "loosen up" the soil in the container while it's submerged. The more tunnels you create, the better. The skinnier the stick the better so you don't tear roots. Most of my citrus trees are in the Gritty Mix where I don't have any such issues. I also rest easy when it's pouring rain outside knowing they won't be drowning. However, the gritty mix is a bit of work to make and cannot be purchased. The ingredients can be expensive but they last for a very long time. The bagged mixes are meant for shorter term - like 1 year (or 2 years MAX) before needing full replacement. How long one can make it last depends on how healthy a tree you are wanting.

I am no pro on indoor plants. But 1st thing I would have is a moisure meter About 4 bucks at lowes. If moisture is correct then I would think about the soil. Most liquid fertilizers lock up nutrients over time. The soil might need to be changed. If it is in real tight in the pot a hack saw will cut it off real nice and quick. New soil and proper moisture cures most things. A treatment of fungicide while it is out of the pot is in order. I am a new snake oil convert. I use super thrive it works for me. You proably have some type of mineral defieciency. Well this covers 99.9% of possible problems. Domestic animals could be another source of your problem but then the above would cure it for a while. Good Luck, Jim

same problem here...in Maryland. 3' plants in raised beds. noticed some wilting on one plant a couple of weeks ago, it's gotten worse and is only at the top...and just beginning to notice it on another nearby. seems to get worse in the later afternoon. We raised most of these from seed...San Marzano type. i did use Llama dung to augment the soil, but did that last year also. I used 1-2 sheets of newspaper as a weed barrier with an inch or two of straw over that. I had great luck last year with nearly the same method, but used grass clippings over the newspaper. I water as needed, when we have no rain. No walnut trees...they get sun from about 930a-5p. any thoughts????? Help!!!

I'm quite sure after reading this thread that i have an answer for my early girls, which are all doing this thick leaf stem growing upwards and twisting (more like a sucker would do), with large, thick leaves that are also turning upwards and rolling/twisting. There is zero discoloration or otherwise poor health indications, i grow in the middle of 50 acres, totally organically, my own compost used, mulched with wood chips a year old from within the property. I've used zero pesticides, herbicides or fertilizers. Just compost, coco coir, water and my seedlings. They aren't stunted, are growing quite fast actually but, here in Northern California in the Sierra Nevada mountains we've seen record breaking temps between 90-105 for a few weeks straight now and I'm pretty certain my plants are just tired of baking. I'm hanging shade cloth tomorrow and will post pictures as well because it's quite bizarre how hearty they are but growing like an upside down tipi (and it's only my early girls doing this, the other varieties are all fine.)