too small a pot.. for too large a plant.. on too windy a balcony with too much intense sun complicating the watering issue ...

fertilizer is not a fix all.. stop ferting your plant .... 3 times in 15 months is too much.. unless you are doing it in a highly diluted manner ...

your plant is severely stressed.... stop doing things to stress it ... i would probably not repot it.. while its holding fruit.. unless you just want those to abort ....

on some level.. you might be loving it too much ....

ken

Ken is correct, your tree needs to be transplanted into a larger container+

Don't agree! To me the stem looks quite thin for a pot of that size. Unless the roots are completely filling the pot there is no need for a bigger pot. Over potting is not good - it can lead to wet areas where the roots don't penetrate.

But I do think sun scald is a possibility. I'd keep it shaded from midday sun.

I agree with Citrange

Couple things, it sounds like you've done a lot to this tree, fertilizer, citrus soil, fungicide, etc. You could be dealing with fertilizer burn, read the bag for your citrus mix. Many have a 6 month slow release fertilizer mixed in. If you add fertilizer you're overfertilizing your tree. The fungicide can add stress, and then you may have heat stress. I would definitely repot into new soil, make sure you read the bag this time so that you know what you're working with, then water the tree deeply and when a skewer inserted in the soil feels dry or doesn't have soil clinging to it. Let the tree be. Address problems when they arise and be sure that the problem you're treating is the actual problem with the tree.

Thank you very much, everyone! To answer some questions, I've fertilized with half the amount of recommended fertilizer, which ultimately came out to 2 tablespoons diluted in a gallon of water, three times in 15 months. I did look up the soil bag and YES it does have "plant food" in it? Perhaps that's the culprit? So would it be better to change the soil or wait this one out and keep flushing?

Regarding heat stress, it's really never above 75 or 80 tops but maybe the reflections from the building are heating the plant up more. And one other note, there's a giant sweetgum tree in front of my balcony and the leaves came back in weeks before this browning happened which means it happened when the tree has been receiving less light but could the effect be delayed?

The midday sun actually doesn't hit the tree but the afternoon sun (after like 2pm) does. I've attached an image of the brightest part of the day.

I thought about repotting but was thinking it's still too soon for a bigger pot and I would have more trouble with soil moisture management.

Someone else suggested the tree might even have a bacterial infection.

Last question, I would love to stop using distilled water ($$ and SO much plastic) and I wonder if I lay off everything else if I might try tap water again.

I really appreciate everyone taking so much time to answer my questions!!!! Sounds like I should stop trying so hard

to fix my tree and just let it be!

I, personally, would just keep it in the current size pot. As long as the roots don't fill the pot, you're good. And a bigger pot and your watering is going to be problematic. I would repot, just to start fresh and alleviate any concerns. The fertilizer in the mix isn't necessarily problematic, you just want to know that it's there so as to not overfertilize. Something else that can be helpful is to look up bonsai, because, essentially, that's what your tree is. Look up your local water report, what is your water's PH and why. You may be able to just add a bit of vinegar if it's too basic. If not you could just get a cheap filter and that might help too. No need to use distilled.

98% of struggling plants in California is not enough water. Oakland has a great 10b climate. It's not the weather. A bigger pot would help and drop some Vigoro Citrus fertilizer on it.

lol. You don't live in California I can tell. Even outdoor potted plants don't' get enough water.

Stan, the OP doesn't live in southern California. Your snide remarks are not needed either.

I'm leaning more toward @Ken B Zone 7 than @stanofh 10a Hayward,Ca S.F. bay area. I check the moisture religiously (with a meter and a stick). Between here and Reddit I've been given advice ranging from water more to water less to protect it from the sun to fertilize it more to fertilize it less to put it in a bigger pot to keep it in this pot to get some ladybugs to have it tested for bacterial infection to use distilled water to stop using distilled water and switch to filtered water! Ultimately I think I am messing with it too much in general and do need sandier soil and more drain holes so the roots can dry out more but it seems prudent to wait til after the fruit sets, given how much "love" I've given the plant, ha ha. Thanks again, everyone!!!!

I would call Oakland, California - as California. Where did I say socal?

More plants are killed by overwatering than not enough water. It looks like sunburn to me. Back off on the fertilizer, too. It's not a cure-all. I think we're all assuming that the container has a drain hole. Growing citrus in containers

Actually, the roots of a container tree does not die from the water when a tree is over watered. It dies from a lack of oxygen. Same thing from medium compaction, lack of oxygen.

Just wondering if that pot has drainage holes? It looks like an ornamental cache pot to me, rather than a container designed for planting in.

@floral_uk z.8/9 SW UK @lgteacher it has drain holes and i drilled extra holes.

That’s good.

In California that old chestnut about overwatering is reversed. People in wetter climates just don't get it when plants here are always wanting water.

Sunburn on citrus in Oakland? Only if kept too dry in a pot.

You can certainly overwater citrus in California. It happens quite often. They can also be underwatered. California is not the only place in the country that is dry or has dry seasons.

No you cannot and I wish you would realize east coast z7 or even a California foothills z7 are not like lowlands here up and down the state. None of the citrus can live on rains,and so in pots that translates into a need for constant soil moisture.

There might some old Citrus plant in ground that found groundwater or gets shade from large trees that can survive an abandoned garden. Odds are not good.

Your insane to say that you can't overwater a citrus tree in California. Of course you can. I'm done with this conversation.

A lot has to do with the porosity of the medium.

Wait a couple days after you thoroughly soak the plant. Sometimes when you see water come out the bottom it is just going down the sides, and the inside root ball is dry. Lift the plant (get a friend if it is too heavy, or turn it on its side and slide it out sideways and take a good look at the roots. Fork around to the center of the roots to see if the whole rootball is getting wet. Citrus should get fertilized once a month year round. Better to err on the lighter side for a container plant, but be consistant. I think the leaves look like sun scald. Fertilizer burn on most of my plants shows up around the edges of the leaves. A tablespoon of vinegar in a couple gals of water should take care of alkaline water problems. Plants need minerals too, and distilled water has all those romoved.

Sometimes too much love and care can kill a plant. Go out there twice a week and give it a drink and relax. You can always buy meyer lemons locally.

-Babka (from down here in Silicon Valley).

The only way a Lemon gets sunscald in Oakland is if its kept too dry.

I agree with you stanolfh, that is why I think the whole inside of the rootball is not getting water. Too much water would creat root rot, and the leaves would droop and die. Only one way to confirm that. Pull it out and peek inside.. Once the "medium" (soil stuff) gets dry it repells water like dry peat moss, or pouring water over flour in a cup. I've had a lot of that recently with some of these newer potting "mediums".

Nothing to lose to take a look at the roots if the top is having problems. They are connected, you know.... ;-)

-Babka