Japanese Black Pine browning tips

[LupercusPNW]

Hello all,

I have some experience with bonsai, 3-4 years, but no real training. This Black pine was a new addition this winter and recently it's begun having brown tips. I have never had a pine, but from my research they lose their old needles very slowly, but at the same time once they show signs of needles dying it's often too late. So, I just wanted to verify that it is not dying, just cycling.

When I bought it as nursery stock, it was fully green, and had both long and short needles. I re-potted into this training pot mid-February, and it seemed to be doing fine until a couple of weeks ago when the long tips started to brown, so far all the short needles are green. It's in a well draining vessel, I only water when the soil is no longer wet, gets full sun, started fertilizing with miracle grow at 50% 4 weeks after repotting. Is there anything I should be doing? Something I'm doing wrong. I'm sure it's just the needles aging, but I've never cared for a pine, and I don't want to kill it by over/under watering it when there isn't anything wrong to begin with. Thanks!

 

[0soyoung]

Consult the flow-chart-for-diagnosis-pine-problems, in the BNut Resources.

 

[RobC]

Would you need to cut the brown tips off? Or just let it be?

 

[River's Edge]

Hello all,

I have some experience with bonsai, 3-4 years, but no real training. This Black pine was a new addition this winter and recently it's begun having brown tips. I have never had a pine, but from my research they lose their old needles very slowly, but at the same time once they show signs of needles dying it's often too late. So, I just wanted to verify that it is not dying, just cycling.

When I bought it as nursery stock, it was fully green, and had both long and short needles. I re-potted into this training pot mid-February, and it seemed to be doing fine until a couple of weeks ago when the long tips started to brown, so far all the short needles are green. It's in a well draining vessel, I only water when the soil is no longer wet, gets full sun, started fertilizing with miracle grow at 50% 4 weeks after repotting. Is there anything I should be doing? Something I'm doing wrong. I'm sure it's just the needles aging, but I've never cared for a pine, and I don't want to kill it by over/under watering it when there isn't anything wrong to begin with. Thanks!
View attachment 295112

The primary discolouration is on the older needles, there is some evidence of needle cast on the older needles. This can be seen by the bands of brown/red around the needle with green on either side. The focus on the new growth is not great but I would check for similar banding on the new needles!
If it is evident on the new needles than consider treating with an appropriate fungicide. For a start I prefer Daconyl, on more serious cases or valuable trees I use a systemic product called "Infuse".
If it is not evident on the new needles forming and opening then I would give it lots of sun in a site with good air movement and focus on appropriate watering. You may cut off the dead portions of the old needles, including banded sections. Otherwise I would keep as many healthy needles as possible.

 

[LupercusPNW]

Thank you River's Edge! That other chart was informative but left me lost.
None of the smaller needles show any discolorations. I'm following your advice and am going to clip the dead portions and probably raise it up. It gets full sun, but it's behind a railing and I've wondered if it's casting too much of a shadow on the tree.