Hello everyone.
I'm new on this forum, I'd just like to quickly thank you all for having me.

This lovely Carmona Bonsai was gifted to me in March and have been taking care of it ever since. I am, however, quite new at this. I've made sure to read up whatever I could find to properly take care of this lovely tree and it has been smooth sailing for the most part. Even moved it to the kitchen where it catches some direct sunlight for an hour or two in the morning (from around 8 am to 10:30-ish pm) .
Then, a few weeks ago I noticed a lot of leaves started to fall.
I'm not sure what might have caused this. My suspicions fall on me perhaps overwatering it (summer's been pretty warm) but I've always made sure the soil was starting to dry before giving it any more water. I pruned a few leaves that had gotten big since I was advised those could block light for smaller ones. Since then I have cut back on the water, only occasionally spraying a little water on the leaves if the temperature is high. Also moved it back to the living room where the temperature isn't as hot. I noticed some white-powder-like stuff showing up at the base of the trunk (can't really see it much in these photos as I watered it today and it seems to have washed away).

This is its current state(pictures taken shortly after writing, as the soil was getting dry and I didn't want to risk it getting dryer). Lots of leaf loss, mostly on one side. Ever since I moved it back to the living room the leaves have gained a more greenish hue again.




I'm hoping someone here might give me some pointers as to what to do. What might I have done wrong?
As I've said, I'm very inexperienced in bonsai care, but this tree has a very special meaning to me and I do not want to lose it. I'll appreciate any insight and/or advice you folks can give me.

Kind regards,
Peter.

It needs sunlight, and lots of it. An hour or two filtered through a window just isn't enough.

The tree should be outside in the fresh air with hours and hours of sunlight.

And by the looks of all that moss /algae on the soil its waaaay too wet.

Thanks for the advice, Ivan and LucR.
I'll try to have it outside during the day. Direct sunlight would you say? The sun here can get pretty hot in summer and I heard that might end up being harmful.
It was recently watered, as the soil seemed to be getting quite dry. But I'll let ti dry some more next time maybe, so most of the moisture gets out I supose.

Anybody in the world will tell you the weather here is pretty hot in the summer. My sister in law apologized for the brutal heat wave, at 76F, when we visited them. We laughed because we keep the air set at 78F.

Trees don't know how to read the thermometer and they absolutely love sun. Take a little bit of trouble to keep the soil in the pot cool so the roots don't burn, and be sure to water it, but it should do fine.

I said all that. Check the species to see what the tree's requirements are. If it grew up in central Ontario and you are in central California it may not be that simple, but the tree wants sunshine no matter what.

I've been leaving the tree outside during the day only bringing it inside at night. Some of the leaves seem to be slowly regaining their greenish hue. As for watering (which i think was my biggest mistake, over-watering), the soil is still humid so I'm only spraying (one puff) in the early morning. Hopefully my tree will regain it's strengh.
Should I be worried about root-rot? Because of overwatering it.

Why would you bring it inside? Trees dislike being moved around.
The right way to water is wait till the soil feels dry to the touch and water then thoroughly with a garden hose till water runs from the drainage hole underneath the pot. Do not water on a schedule

In the summer all of my tees are watered every day, If it raining then I wait for it t stop and then water, unless it is heavy and for hours. Trees need water to transpire to cool down without it they will suffer and in extreme cases die.

lucR wrote:

Why would you bring it inside? Trees dislike being moved around.
The right way to water is wait till the soil feels dry to the touch and water then thoroughly with a garden hose till water runs from the drainage hole underneath the pot. Do not water on a schedule

Well, I was given to understand the Carmona was an indoor bonsai. As in, as long as it has good access to light and water it could be kept indoors. Even says so on this website and every other around. People I've spoken to have said the same. But maybe I have this all wrong?
I live in a flat so at one point or another during the day, the sunlight will no longer shine on the plant, hence I move it when I'm able so it catches as most as possible.
Temperatures here in Portugal, while warm during the summer, reach freezing temperatures during winter, so I'm thinking it's not a good idea to leave it outside during that time, save for sunny days.

Valtiel wrote:

I live in a flat so at one point or another during the day, the sunlight will no longer shine on the plant, hence I move it when I'm able so it catches as most as possible.

Valtiel, bem vindo ao Bonsai Empire.
Vou responder em Inglês por respeito aos outros que não nos entendem.
Plants in pots hate being moved around. Find a sweet spot where your Carmona thrives and keep it there.
Many flats in Portugal have strong winter heating systems, which control the temperature but...
They dry the air and plants inside will suffer from lack of humidity
Carmona can be kept indoors, as long as they have light, humidity and fresh air around them. But they can be fussy.