Japanese Black Pine needle browning

[gustakasn0v]

Hi BonsaiNut crowd,

Hoping to get some help from you as a new Bonsai owner. I’ve been growing this JBP from seed since Aug 2021, repotted in March 2022 as the roots were outgrowing the tiny seedling pot. It’s been healthy this entire time, but I went on holiday last Friday and came back Sunday to find the top needles and some of the bottom ones browning from the center outward. There was lots of sun and low temperatures that weekend, but I didn’t worry about watering as typically the big pot can hold lots of water.

Some details about the site:
- South-facing windowsill in London. Sunlight is an issue of course, but so far it hasn’t seemed to cause problems and south-facing means it gets a good chunk whatever sunlight there is throughout the day
- Temperature is usually 21-23C, there’s a radiator nearby (a meter away) but it’s usually off, but it did turn on about two weeks ago due to the cold.
- I haven’t left the pine outside. I just read some threads suggesting JBPs don’t do well indoors, perhaps that’s a problem?

I’ve read some of the other threads around this, some of the things I’ve considered, I may be wrong though :
- Fungus: unlikely because I don’t see any spots in the needles, they’re browning from the center outward instead of banding, and there’s 2 other identically aged trees around it unaffected
- Under/overwatering: the pot is large with (what I think is) appropriate drainage, and I follow a weather-based watering schedule from the Planta app. I’m thinking over-watering but can’t be sure unless I inspect the roots for root rot I guess
- Fertilising: the kit i bought the seeds with comes with liquid fertiliser to be diluted, and suggests that on early stages I should fertilise them every two weeks. I’m wondering if this tree is no longer at that early stage and if it’s instead getting overwatered and getting root rot

What could be happening? And is there anything I could do? I would very much appreciate any help you can give me, and will provide you with any additional info you may need

 

[leatherback]

It is soaking wet substrate which is what pines do not like. It is indoors which pines do not like. It is next to a heater which pines do not like. It is being fertilized in a period where it should be dormant which is sub-optimal.

I am venturing a guess what you see now has been weeks, months in the making.

I am in serious doubt this will come back from this.

 

[Paradox]

Agree with the above.

Pines should not be in potting soil. It doesn't drain properly and stays too wet. A common saying in bonsai is that pines do not like wet feet (roots)

Should be dormant in winter

Should be outside or at least in a protected area (ie coldframe outside) that is MUCH colder right now for dormancy

Looks like it's growing new buds at the top at the wrong time of year without having energy reserves from being dormant over the winter

Inside with the heat on = way too dry air

Being in a window on a strong sunny day = baked foliage

Lots of mistakes at once will pile up and kill a tree. I also doubt the chances of survival are good

 

[Potawatomi13]

What is personal location? Best suggestion to put outside and MAYBE will grow in Spring if Winter not too frigidly cold. Maybe too far gone already

 

[gustakasn0v]

Thank you @Paradox and @leatherback for your help! Sounds like I have a lot to learn still, I’m grateful for your guidance

Some tactical questions:
1. Looks like this needs repotting with soil that improves drainage, and being outdoors. Since the other two trees are still healthy and have near identical current conditions, is it safe to do these changes now, or should I wait until Spring? If it’s safe I’ll even attempt it on the dying one to see if I can save it, although my hopes are low.
2. Do you have any resources (books, videos, training, etc) I could get to better learn the basics? I reviewed some links on this forum including https://www.bonsainut.com/threads/how-to-be-a-successful-bonsai-beginner.48994 and frequently watch videos, but I feel I’m lacking a more comprehensive and guided ‘getting started’ resource and don’t know where to go.

(@Potawatomi13 I live in London UK)

 

[JeffS73]

Hi Gustakasnov,

I'm afraid your JBP is likely dead, for the reasons suggested above. I'm sorry for your loss if you've nurtured this from seed! Some species will tolerate living indoors, but most will not. I suggest you turn your attention to your other two trees, what species are they?

 

[Shibui]

It is generally a little warmer here through winter but I repot pines any time from mid winter through to mid spring. There's not much you can lose by repotting the pine shown. I agree with the others that it looks to be far too late to save it now. If others are healthier I'd be looking for a spot outside where they can get some natural sun when it shines. Provided the pots are not watered too often and not sitting in trays of water potting mix should drain well enough to keep them healthy until spring repotting time.
Add the location to your personal profile so you don't have to remember to keep writing each time. Location can mean a big difference in advice and timing for bonsai.

 

[gustakasn0v]

Hi Gustakasnov,

I'm afraid your JBP is likely dead, for the reasons suggested above. I'm sorry for your loss if you've nurtured this from seed! Some species will tolerate living indoors, but most will not. I suggest you turn your attention to your other two trees, what species are they?

They are all JBP, and the other two are much healthier. I’ve attached a few pictures

It is generally a little warmer here through winter but I repot pines any time from mid winter through to mid spring. There's not much you can lose by repotting the pine shown. I agree with the others that it looks to be far too late to save it now. If others are healthier I'd be looking for a spot outside where they can get some natural sun when it shines. Provided the pots are not watered too often and not sitting in trays of water potting mix should drain well enough to keep them healthy until spring repotting time.
Add the location to your personal profile so you don't have to remember to keep writing each time. Location can mean a big difference in advice and timing for bonsai.

Thanks for the advice! I’ll update my location. I’ve moved them outside, it’s a balcony so it’s sheltered from excessive rain and wind. I could even get a hanging pot to put them on the railing closer to sunlight, thoughts?

I’m considering taking them to a nearby bonsai nursery so they can better advise on repotting now and trimming any root rot, what are your thoughts on that?

 

[Shibui]

I’m considering taking them to a nearby bonsai nursery so they can better advise on repotting now and trimming any root rot, what are your thoughts on that?

Local advice is vastly preferable to someone offering from halfway round the world and from very different climates. Mostly nursery advice will be conservative (which is good for those starting out)
Orientation of balconies, etc can have a big bearing on how plants will perform. Pines generally do better with full sun exposure. Next best is part sun. North facing balconies up there will obviously not have much direct sun exposure. West facing can sometimes get too hot in summer. As you are in sunny London I guess the more direct sun you can give these pines the better so hanging closer to the railing will probably eb a good idea but without knowing orientation and sun exposure it is harder to be sure from way down here.

 

[gustakasn0v]

Local advice is vastly preferable to someone offering from halfway round the world and from very different climates. Mostly nursery advice will be conservative (which is good for those starting out)
Orientation of balconies, etc can have a big bearing on how plants will perform. Pines generally do better with full sun exposure. Next best is part sun. North facing balconies up there will obviously not have much direct sun exposure. West facing can sometimes get too hot in summer. As you are in sunny London I guess the more direct sun you can give these pines the better so hanging closer to the railing will probably eb a good idea but without knowing orientation and sun exposure it is harder to be sure from way down here.

Thanks for the reply!

I’ll take them to the nursery soon and see what they say.

It’s a south-facing balcony (I wrote it when opening the thread, but it was a long blurb so I understand it’s easy to miss). My primary concern with a hanging pot is over-exposure to wind as it’s been windy this year. Rain doesn’t worry me as I can always put them elsewhere to prevent over-watering. Are JBPs sensitive to wind?

 

[Srt8madness]

Shouldn't be, they're coastal trees in Japan. Idk about freshly repotted seedlings though. Make sure to mention that part when speaking to someone locally.

 

[gustakasn0v]

Update: the bonsai with the browning needles has died; the other two are better, especially the one with the small plastic pot. The bonsai nursery didn’t advise repotting so soon after the last time, and instead suggested I update the watering schedule, place them outside, and use a seaweed foliar feed. I’m hopeful now that spring has started, but I’ve also moved to a north-facing flat with no balcony which surely won’t help with the lighting. I’ll see how the trees progress, I may have to find a different location for them, or donate them and try again with trees better suited for my weather and location. I’ve also learned via the bonsai subreddit that raising bonsai from seed isn’t recommended for beginners, so I may try my luck with junior bonsai instead.