Hello! I'm very new to bonsai and I've had my fukien tea tree since about July 26th. Since then I've repotted it into a bonsai soil mix. It sits indoors on my nightstand and gets afternoon sun, I water when the soil is almost dry (pretty much 2-3 days) via bottom watering/submerging the pot in water up to the rim. She seems to be doing fine, except...

The last few days, I believe I have a fungus problem. I sprayed fungicide Saturday, July 30th due to seeing several leaves with both black, brown, and what looks like powdery mildew? But even though I sprayed, leaves keep popping up with black spots I've been removing any affected leaves I see, however, I decided to ask for help because it's starting to become a lot.

Here are some example leaves:

And here is the full tree for reference:

I don't know what I'm doing wrong. I haven't started using fertilizer yet because of this problem. I don't want to remove too many leaves anymore but I don't want the fungus to get an opportunity to spread. The black spots have been appearing on both old and new growth.

Could it be a root issue? Should I repot again? I read that the carmona's roots are very sensitive though... Is it a light issue; should I invest in a grow light? I don't know what I could be doing. Should I just wait and keep removing leaves, spraying fungicide as per instructions on the bottle? The tree has started looking sad because at this point, so many leaves have had to be removed...

Any help is much appreciated. Thank you in advance

Hey, those little white spots are a normal characteristic on Carmonas, there's only a leaf there with some white stuff on it, and I think it's from the tapwater.

To be honest, the full tree picture seems like a happy tree for me, but yes, those black tips could be fungal, but also could be a soil too damp, copper based fungicides are good on preventing fungal issues, and avoid the sporus from spreading, but it doesn't "cure" the plant from many of those fungal issues, that's why removing the bad leaves can help you, however to cure from most fungal pathogens systemic fungicides are required (that actually gets into the plant's physiology), but I would say for you to wait, remove the bad leaves, if you're using copper sulphate you can apply twice a month on the recommended proportions and see how it goes.

Oh my gosh, thank you so much for replying!! I know of the natural spots, but I was referring to the more mildew looking spot the one leaf had! Maybe it's just markings from the tap water like you said, though!!

The fungicide I'm using currently is Gardensafe's Fungicide 3, I think the main ingredient is neem oil—would that be good enough or should i try for specifically a copper based fungicide? Do you have any recommendations for systemic fungicides?

Thank you so much for your time and advice, I greatly appreciate it!!!!

Well, this one you use should be okay.

If you want to use Copper Sulphate, that may be found in any Agricultural Supplies store, it's largelly used on grape cultivation and it's just a mineral, it even helps on the leaf/tree health.
Plus... It's really cheap, at least here, you can get probably an amount that will last you a few years (for a lot of plants) under a dollar, I use it monthly on the growing season for species more susceptible to fungal issues, like Delonix.

Now about systemic fungicide, there was only a time or two that I had to use it, so you must know it's for more tricky situations, the one I used you probably don't have there called "Forth Fungicida" based on Difenoconazole, from Triazoles... But that Idk where would you find that there.

And for now, I don't think that's what you need to be honest.

Oh, I'll go ahead and stick with the one I have for now then, but if it gets worse I might get some copper sulphate!

I greatly appreciate your advice, I'll work hard to keep the tree healthy!! Thank you so much!!!

Since you kind of asked what you are doing wrong:

You repotted a newly purshased tree within days after purshase. Thats wrong. Judging from your post it seems like you are a beginner and did it yourself. That is recepie for disaster.

You water by submerging. That is wrong. Doing on newly repotted tree even worse.

I asume you are in the northern hemisphere and that it is summer now? Do not keep trees indoors in summer, they need to come out into the elements they are adopted to.

But the biggest misstake was done pre purshase. You shosed a species that I have never seen grown healthy by a hobbyist. We have 100s of "help my Carmona is dieing" threads here at bonsai empire. Some well meaning members tries to give general advice. But the fact is that none of them have shown a long term healthy carmona.

Before anyone prove me wrong, my statement is that carmona cannot be grown in temperate climate. Indoors is too dry and outdoors they freeze to death in winter.

Sorry to tell you. That tree have the same chanse of survival as cut tullips sold in spring by the very same garden centers that sells carmona. It is business, not hobby. Get yourself a decent locally hardy garden material and start the project on turning it into bonsai outdoors. That is what the hobby is about.

Yeah I am very much a beginner, I didn't know about specific times to repot until way after. It was the employee at the local garden shop that recommended the tree to me; I hadn't known a lot about bonsai until now.

May I ask why submerging is wrong? I haven't heard anyone say that it's wrong before. I'm sorry I don't know.

Yes, I live in the southern US, zone 7a.

I'll go with a locally grown tree next time, but I do want to try my best to keep this carmona alive since it's in my care now. I unfortunately live in an apartment so there aren't a lot of options to put the tree outside. Thank you very much for replying and for your advice!!!

Submerging trees adds water but depleats oxygen and may cause root rot. Especially after root work as there are wounds that easily rot.

Correct watering is with a fine nozzle (garden hose, watering can etc). Water abundant over all the soil surfase until water is pouring out the drainage holes.

I do understand why submerging is recomended for "indoor" trees. Quite messy to water correct indoors.

Good luck with your tree. And please come back in a year and report how it worked. All experiences good or bad helps to solve the riddle called carmona.

Oh, I see!! I knew about the potential root rot, but not about the oxygen part! I'll invest in a small watering can!

Thank you so much for your tips and guidance!! I'll do my best!!

Pouring water from above soaks the soil, then runs out of the drain hole, and siphons extra water out, pulling fresh air (including oxygen) into the soil. The water running out also can pull some minerals that have collected out. Soaking in a tub does not have the same effect.