Bonsai branches black? Help?

[Roidling]

I am new to bonsai and have been looking after this Ilex Crenata, Japanese holly Bonsai, for about 6 months.
I originally kept it inside, but due to the low humidity inside, I have been regularly keeping it outside (UK spring/summer).
Now, my tree is slowly looking more sickly: many of the branches have died, leaves are brittle and falling off. I am disappointed as I don't know how to get the lower-growing branches back (they looked very nice). My branches are turning black, and I don't exactly know what is wrong with them. I initially suspected some sort of soil fungus.
Some algae was growing on the topsoil, which remained there for a few weeks before I removed it, but apart from that, what can I do to help it recover
The bonsai means a lot to me so any help would really help!

 

[Wires_Guy_wires]

Algae can only grow if the soil is constantly wet.
Like wet, wet.

That's a key issue to fix.

Black dead branches are normal, as in: if they're dead, they can turn black due to desiccation and oxidation of their internals. That's not a problem if the rest of the plant is healthy.

I don't know a lot about the species, so I'm not sure if they naturally bud everywhere once they're in good health. But I assume they do. So make its health your priority and the rest of the bonsai journey can continue.
Tell us for instance what soil it's in. Take a picture of it and post it here. Usually there are a couple people that will chime in and help you forward.

 

[Shibui]

Agree that algae growing on the soil would probably indicate very wet soil. Very wet soil effectively drowns roots or they get root fungal diseases and die. Without enough roots some top branches will die.
Need to check soil and roots to see if too much water is the problem. If so, letting it dry a but between watering should help. In really bad cases emergency repotting can sometimes help.
If you have not been watering much or watering properly the root ball can get too dry. This also causes branches to die so need to work out what the problem is before making changes.

 

[Potawatomi13]

Wet soil? Does pot have drainage?

 

[penumbra]

You don't show a picture of the soil, but I know that many times people on this site and elsewhere have called moss algae. So that is one issue, was the soil too wet or not? Often when out door plants are brought inside over watering can be an issue. The tip dieback does not look like over watering to me. It does look like what you would expect from an outdoor plant being grown indoors in less than optimal conditions. You don't give any information on your indoor growing conditions, but typically indoor humidity is significantly lower than outside humidity. With the limited information you have provided, my advice is to get it outside in at least partial sun right away. This is where it belongs. Generally it takes pretty advanced plant care knowledge to keep an outdoor plant inside for any period of time. You will have to determine whether or not the plant is being over watered primarily by soil condition. Soil surface does need to dry out. Again, a general comment is that people who try to keep an outdoors plant inside, are also the people who may not quite understand the plants watering requirements. I do wish you the best of luck but please put this poor plant outside where it belongs.

 

[Roidling]

You don't show a picture of the soil, but I know that many times people on this site and elsewhere have called moss algae. So that is one issue, was the soil too wet or not? Often when out door plants are brought inside over watering can be an issue. The tip dieback does not look like over watering to me. It does look like what you would expect from an outdoor plant being grown indoors in less than optimal conditions. You don't give any information on your indoor growing conditions, but typically indoor humidity is significantly lower than outside humidity. With the limited information you have provided, my advice is to get it outside in at least partial sun right away. This is where it belongs. Generally it takes pretty advanced plant care knowledge to keep an outdoor plant inside for any period of time. You will have to determine whether or not the plant is being over watered primarily by soil condition. Soil surface does need to dry out. Again, a general comment is that people who try to keep an outdoors plant inside, are also the people who may not quite understand the plants watering requirements. I do wish you the best of luck but please put this poor plant outside where it belongs.

Thanks for the detailed reply, I kept it indoors for a few months, but I believe it was kept well. I used a humidifier in my room and used a mister with a pebbled-filled humidity tray underneath it. I also kept ventilation as much as I could in the room. However, there was white build up on the leaves and I was unsure about the sunlight, so I moved it outside.
I know the difference between moss and algae, and it was most certainly algae. Compounded with that, I took a look at the roots today, and they were very black. Root rot?

 

[Roidling]

Wet soil? Does pot have drainage?

Yes drainage hole with the pot, however, it uses garden centre soil - not exactly the right mix for it I believe. Does anyone know a good soil mix for evergreen bonsai?

 

[Roidling]

Agree that algae growing on the soil would probably indicate very wet soil. Very wet soil effectively drowns roots or they get root fungal diseases and die. Without enough roots some top branches will die.
Need to check soil and roots to see if too much water is the problem. If so, letting it dry a but between watering should help. In really bad cases emergency repotting can sometimes help.
If you have not been watering much or watering properly the root ball can get too dry. This also causes branches to die so need to work out what the problem is before making changes.

Thank you! Yes, I do believe overwatering was the issue, I took a look at the roots today and some of them were black or brown and mushy. What are healthy roots supposed to look like? I haven't had a clear image online.

 

[Shibui]

What are healthy roots supposed to look like? I haven't had a clear image online.

Healthy roots have white tips. Colours may vary depending on species but certainly won't be black and mushy.
In cases of soggy soil and root rot you can try to water less and get the soil drier but that's often difficult after it has progressed to this stage.
Emergency repotting may be the best option even though timing is not best. Leaving a tree in bad soil conditions is almost certain death. Out of season repotting is only possible death. Not always 100% success because often the tree is just too far gone and would die in any case. This one looks to still have plenty of life but you will need to choose which way to go for yourself.

 

[Roidling]

Healthy roots have white tips. Colours may vary depending on species but certainly won't be black and mushy.
In cases of soggy soil and root rot you can try to water less and get the soil drier but that's often difficult after it has progressed to this stage.
Emergency repotting may be the best option even though timing is not best. Leaving a tree in bad soil conditions is almost certain death. Out of season repotting is only possible death. Not always 100% success because often the tree is just too far gone and would die in any case. This one looks to still have plenty of life but you will need to choose which way to go for yourself.

Thank you, I have trimmed a lot of the dead branches off, and I am looking to repot the bonsai, but do not know the best soil mix for a evergreen bonsai tree? 1:1:1 for Akadama Pumice and Lava rock okay

 

[Shibui]

Thank you, I have trimmed a lot of the dead branches off, and I am looking to repot the bonsai, but do not know the best soil mix for a evergreen bonsai tree? 1:1:1 for Akadama Pumice and Lava rock okay

Soil mix is more about what suits you.
Trees will grow in a wide variety of soil mix. I use the same mix for all my trees and that works well. No need to keep different components or bins of different mix. Everything can be watered similar because it is in the same mix.
If you want to use different mix for each tree that's totally up to you. If you normally use 1:1:1 that should be fine for your holly provided you can manage watering to suit that soil.

 

[Deleted member 47471]

Thank you, I have trimmed a lot of the dead branches off, and I am looking to repot the bonsai, but do not know the best soil mix for a evergreen bonsai tree? 1:1:1 for Akadama Pumice and Lava rock okay

Most literature cautions against repotting a currently sick/weak bonsai tree because the overall stress compounds the problem/disease plaguing the tree, making it less likely to survive the repot. If/when you can verify corrective action was successful, it should be safe to repot, provided repotting falls within the parameters. (Following to track and learn more)

 

[Paradox]

Most literature cautions against repotting a currently sick/weak bonsai tree because the overall stress compounds the problem/disease plaguing the tree, making it less likely to survive the repot. If/when you can verify corrective action was successful, it should be safe to repot, provided repotting falls within the parameters. (Following to track and learn more)

While I agree, if the soil is too wet to the point it's rotting to roots, waiting won't fix the problem. You need to improve drainage and get that soil to dry out.

I had a JBP that was staying to wet. I lifted it from the pot and saw that fine roots had clogged the drainage holes. I cleared those and put a layer of gravel on the bottom so the tree sat higher in the pot. I was more careful about watering for the rest of the year. It helped the problem until I was able to do the repot at the right time.

 

[Shibui]

Most literature cautions against repotting a currently sick/weak bonsai tree because the overall stress compounds the problem/disease plaguing the tree, making it less likely to survive the repot. If/when you can verify corrective action was successful, it should be safe to repot, provided repotting falls within the parameters. (Following to track and learn more)

If the soil is killing the tree it will not survive long enough to recover so no need to repot in future.
If your care is killing the tree and you can change that's a different matter and it is possible to wait for better timing.
I have had several cases where out of season emergency repots helped trees recover successfully.

 

[rockm]

Most literature cautions against repotting a currently sick/weak bonsai tree because the overall stress compounds the problem/disease plaguing the tree, making it less likely to survive the repot. If/when you can verify corrective action was successful, it should be safe to repot, provided repotting falls within the parameters. (Following to track and learn more)

This plant is struggling and the source of that struggle is the soil (which is potting soil, apparently) and indoor conditions.

A complete soil change is a preferable gamble at this point, as its current condition is likely to only get worse. Japanese holly is extremely tough. If done now, the plant will likely get enough going to overwinter successfully--not inside, but in a sheltered corner of the yard, mulched into a garden bed. Japanese holly is hardy to USDA zone 6 (lowest temps 0 F- -10F, so anything the U.K. has to throw at it this winter is unlikely to be a problem.

 

[Deleted member 47471]

If the soil is killing the tree it will not survive long enough to recover so no need to repot in future.
If your care is killing the tree and you can change that's a different matter and it is possible to wait for better timing.
I have had several cases where out of season emergency repots helped trees recover successfully.

great!

 

[Deleted member 47471]

While I agree, if the soil is too wet to the point it's rotting to roots, waiting won't fix the problem. You need to improve drainage and get that soil to dry out.

I had a JBP that was staying to wet. I lifted it from the pot and saw that fine roots had clogged the drainage holes. I cleared those and put a layer of gravel on the bottom so the tree sat higher in the pot. I was more careful about watering for the rest of the year. It helped the problem until I was able to do the repot at the right time.

agreed, fixed, then repot

 

[Paradox]

I should add that while what I did with my JBP was a risk but it was a calculated risk. I knew it wasn't going to get better and it was August at the time. I had noticed the tree languishing behind my other pines and it was going days with the soil too wet. What I did minimized disturbance to the roots and I was able to get the tree through until I could repot in the spring.

I caught it early before it became a real problem through constantly checking on my trees and noting their condition. It worked though, the tree survived.