Recently repotted JBP has browning needles

[Bonsai Nut]

I think the only thing you can do at this point is to wait and see what happens.

This is the best advice. Pines have an annual rhythm where you do work in certain windows of time based on season and where you live. You have to be very careful not to overwork them. If you repot, particularly if you trim roots, you should not do any work to the top of the tree until it has recovered from being repotted, and that normally means to wait a season before you pull needles or prune or cut candles.

Fortunately Japanese black pines are very strong trees. It may recover. But don't do anything else to it this year.

 

[Wulfskaar]

I like to check the What did you do today? thread often. You can see what people are doing at any point in the year. It's interesting to follow and it can be a helpful guide.

 

[The Barber]

Did you bare root it? That could also cause issues.

 

[Bonsaidoodle]

Recently (3/24/25) I removed my 2 1/2 year old black pine from its pot to trim roots. I replanted in same pot with fresh soil. About 2-3 days after repotting, I pulled a good amount of needles and trimmed remaining ones. Some of the top needles on the most mature growth started to brown and now tips of needles I trimmed are beginning to brown as well.

Just wanted to get some thoughts and suggestions from you all. Am I doing anything wrong?
Any advice or comments are greatly appreciated
Thanks!

(4/8/25) 15 days after repot

There has been ton of rain lately. I put a block under one side, keeping it elevated and tilting the pot to ensure good drainage. Haven’t noticed any further browning

Continuing to be optimistic

 

[Bonsaidoodle]

This is the best advice. Pines have an annual rhythm where you do work in certain windows of time based on season and where you live. You have to be very careful not to overwork them. If you repot, particularly if you trim roots, you should not do any work to the top of the tree until it has recovered from being repotted, and that normally means to wait a season before you pull needles or prune or cut candles.

Fortunately Japanese black pines are very strong trees. It may recover. But don't do anything else to it this year.

If JBP has no more visible signs of decline, what should I do during growing season? Do I fertilize or just leave it alone to grow naturally?

 

[bwaynef]

I'd wait until you see signs of improvement, rather than a lack of continued decline, to start fertilizing. Begin slowly and give the tree time to respond. Let the tree lead this dance. If its color improves, or you see more vigor, or budding, give it a bit more fertilizer and watch it.

 

[Desert O'Piñon]

I put a block under one side, keeping it elevated and tilting the pot to ensure good drainage.

Since I really don't know anything about pines (yet), I won't comment on pine care. But I do know that conifers in general really dislike wet/damp roots. I would dare say that most (not all) bonsai pots have drainage holes in the center, so it's possible that tilting it may actually cause the pot to hold more water, not less. Also, if you have a covered area, you might consider keeping it there during rainy spells. After repotting any tree, it's a good idea to limit intense sun exposure and gradually reintroduce it to more sun until it's in full sun, full time. Connecticut is polar opposite of the desert, so it's not quite as urgent there, with your cooler weather and higher humidity.

Welcome to the forum! Your thread has already taught me a few things.

 

[WIlliam_Butler_Yeets]

If JBP has no more visible signs of decline, what should I do during growing season? Do I fertilize or just leave it alone to grow naturally?

Yes, I'd say leave it alone, start fertilizing once it shows signs of regaining strength, if you have other trees, pay attention to them, or if you don't, maybe get a few more. The surest way to kill a tree seems to be smothering it with attention, you always notice something that needs to be done or this that or the other. You can avoid that by having a few more so when you want to mess with a tree you aren't doing the same one or two all the time.

 

[bwaynef]

After repotting any tree, it's a good idea to limit intense sun exposure and gradually reintroduce it to more sun until it's in full sun, full time.

Do with it what you will, but Boon teaches to put the tree back into conditions it was in prior to repotting. If it was in full sun prior to repotting, put it back into full-sun. The additional heat will be beneficial in the regeneration of roots. That's likely caveated with the understanding that the repot happens at the right time of year.

 

[Desert O'Piñon]

Do with it what you will, but Boon teaches to put the tree back into conditions it was in prior to repotting

Thank you, good to know. It's veterans like you that newbies like me need, so we can be corrected before we make the mistake(s).
@Bonsaidoodle , listen to @bwaynef, he knows far more than I do.

 

[Bonsaidoodle]

dead in 3 weeks. Prove me wrong. That happens even when you did everything right.

3 weeks to the day. Consider yourself proved wrong

 

[namnhi]

I hope am wrong! There is no joy in seeing other people's tree dead. So far 10 days from the day I responded to this post. Come back 11 more days from now and show me that it is alive and thriving.

 

[Bonsaidoodle]

I hope am wrong! There is no joy in seeing other people's tree dead. So far 10 days from the day I responded to this post. Come back 11 more days from now and show me that it is alive and thriving.

The picture you commented on was taken 3/24 but fair enough

 

[Bonsaidoodle]

I hope am wrong! There is no joy in seeing other people's tree dead. So far 10 days from the day I responded to this post. Come back 11 more days from now and show me that it is alive and thriving.

It’s alive but not much improvement. I wouldn’t put it in thriving category lol. Mostly I have left it alone to recover. Besides moving it into a spot with more protection when it’s hot, raining and windy, I’ve barely touched it. Not even watering regularly, the rain has done that for me

 

[Orion_metalhead]

I think its a gonner. The low buds which looked like they may be viable look to have dried off.

 

[Bonsaidoodle]

I think its a gonner. The low buds which looked like they may be viable look to have dried off.

You think so? Some of the needles seem to have browned a bit more but they don’t feel dry and the soil has not been lacking moisture because of frequent rain

 

[SeanS]

I didn’t notice the cut needles in your initial post but can see them clearly now in the latest photos. Why did you cut the needles?

 

[Bonsaidoodle]

I didn’t notice the cut needles in your initial post but can see them clearly now in the latest photos. Why did you cut the needles?

Cause I’m a dumb noob lol. YouTube vid said to trim them to improve sunlight getting to back buds
I haven’t done anything to it for a month

 

[Orion_metalhead]

Those buds should be fully extending. I dont have JBP but all my pines are extending now and Im only 2 hours south of you but should be same usda zone.

 

[Wires_Guy_wires]

Those buds should be fully extending. I dont have JBP but all my pines are extending now and Im only 2 hours south of you but should be same usda zone.

They should, but in bad years in my back yard JBP and JRP make that second flush of theirs, the first flush of the year.

I agree it doesn't look pretty and doesn't look promising but if it is truly biologically dead, it would be entirely brown by now. It might still be on the way out though, maybe not this year but the next.
I want to suggest to the topic starter to start looking for new material. One, to keep the hands busy, and two to apply learned lessons, and three because of the time it takes pines to recover. Starting from seed now would result in them being at the same stage once the damaged one is back on its feet.. If it gets there.