Weakened Pine Balancing Act

[Beng]

One of my smaller Japanese black pines had an issue with scale last year. It was my first time dealing with those little buggers! It's been on a toggled regimen of Safari 20SG and Merit 75 since then, as well as neem oil twice in the winter and early spring, and insect growth regulators. Pretty sure I took care of the issue, I took a take no prisoners approach!

The remaining old needles on the tree are discolored and not very healthy. However the new candle growth this spring has been very good. Strong shoots have extended and begun to open well and they are a very healthy green. 1/3 of the lower branches have lost significant vigor through its ordeal. I've been tipping the pot all spring but it's not strengthening those areas. I'll be candle pruning on July 21st here in Brooklyn. In order to balance the trees vigor so that I doesn't loose these important now weak branches, but still not weaken the tree too much from a full decandle do you think it would be better to decandle only the strongest shoots this summer and leave the weaker shoots to grow free? Although every weak branch has a visible bud some have barely extended. This type of winged cork pine which I got from Suthin at Royal Bonsai garden years ago does not backbud often if ever. I don't know the cultivator name. No pics yet but once I get it healthy again i'll take some for you all.

Thanks

 

[Brian Van Fleet]

Do you usually decandle this one? I've had mixed results decandling corkbark black pines. If you can afford the extension, I'd be tempted to let it go this year, and do a little selective pruning in the fall to eliminate anything overly long...

 

[Beng]

I do usually decandle it. Although its definitely less vigorous then a non winged black pine. There have been years i've left it without decandling. What I do different is winter thinning, I leave twice as many needles then I would on other black pines. I'm worried if I don't at least partially decandle the vigorous buds the weak ones may not fully open. Perhaps instead i should do like you suggest and deal with the imbalance in the fall. in the past weak branches have extended fully, i think as the old needles are damaged the pine isn't allocating them the energy they need and is compartmentalizing energy to its strongest buds. What's your experience been decandling winged cork barks?

 

[Adair M]

One key to the cork bark pines is to fertilize heavily. They spend a lot of energy developing that cork, and less so to growing out candles. Since needles are the source of the energy, pulling needles weakens these trees more than the average black pine. So, I would advise that it may be prudent to only pull needles from the very strongest shoots, and perhaps choose another technique to balance energy.

Something else to consider with cork bark: overpotting a bit. Since they are weaker JBP, they may benefit from having a larger mass of roots to sustain them. Maybe choose a slightly deeper pot.

And finally, realize that the corkers really are poor subjects for bonsai. You can't really wire them, if you try to bend a branch, the bark splits off and falls off. It's nearly impossible to not have reverse taper at the base of the trunk where the graft is. So what you have with a corker is a "novelty" tree. You grow it for the bark. If you can get it to have some "style", you're lucky.

If the tree is too weak to decandle, don't decandle it, or decandle only the strongest shoots.

I guess what I'm trying to say is: In my personal opinion, you should not expect to be able to "refine" a cork bark JBP to the same degree of "refinement" that you can a regular JBP. Keeping it healthy is job number 1, and whatever styling you can get out of them is a bonus.

 

[Brian Van Fleet]

Well-put Adair. I do actually wire mine, but they're definitely slower, and when I decandle them, the KY responds ok, as does the Ondae and Hachi-gen. My Taihei threw buds and sat with 2-year old needles until the following spring. I'm working on an article about it, but need a couple more years to photograph some results.

So far, my best results have been to treat them like 5NP...break overly long candles in spring to balance, thin, prune and wire in the fall.

i have been thinking about planting my KY in a bigger pot; Jonas has a good one that seems pretty vigorous, and it also seems to be in a bigger pot. When I repotted mine this spring, it wasn't root bound, as much as it needed to have soil changed, but the tree is 36" tall and in a 16" round. Photo is of the KY.

i feed all my trees heavily, but no more for the corkers...may have to try loading it up.

 

[fredtruck]

I'd like to see a picture of your tree, Beng.

 

[Beng]

One key to the cork bark pines is to fertilize heavily. They spend a lot of energy developing that cork, and less so to growing out candles. Since needles are the source of the energy, pulling needles weakens these trees more than the average black pine. So, I would advise that it may be prudent to only pull needles from the very strongest shoots, and perhaps choose another technique to balance energy.

Something else to consider with cork bark: overpotting a bit. Since they are weaker JBP, they may benefit from having a larger mass of roots to sustain them. Maybe choose a slightly deeper pot.

And finally, realize that the corkers really are poor subjects for bonsai. You can't really wire them, if you try to bend a branch, the bark splits off and falls off. It's nearly impossible to not have reverse taper at the base of the trunk where the graft is. So what you have with a corker is a "novelty" tree. You grow it for the bark. If you can get it to have some "style", you're lucky.

If the tree is too weak to decandle, don't decandle it, or decandle only the strongest shoots.

I guess what I'm trying to say is: In my personal opinion, you should not expect to be able to "refine" a cork bark JBP to the same degree of "refinement" that you can a regular JBP. Keeping it healthy is job number 1, and whatever styling you can get out of them is a bonus.

Thanks i will just partially decandle the strongest shoots then. Once I get it healthy i'll post pics of it. I didn't start taking pics of my trees till this year so I have no great progressions. As for wiring I haven't had any issues wiring younger branches. Obviously wiring one with corking would never work. I definitely have reverse taper going on but that's just part of this type of tree, the bark has its own ideas and you have little control over it. Mines currently a shohin grown as a semi cascade. I too fertilize mine very heavily piling cakes on top of each other this time of year.

 

[fredtruck]

Here's a picture of my Ondae. I just decandled it a couple of weeks ago. Part of the reason I am posting this picture is to show that not all corkers have reverse taper. This tree is a graft, but it was very well done. The other reason I'm posting it is to show that you can style these trees, but you have to go about it in ways different than wiring. For one thing, the falling branches this tree has are natural to the cultivar. Also, I've exposed the roots here. Initially, I did this because I thought the root base was weak, and I wanted to toughen it up. The unfortunate side-effect is that exposed roots call attention to the grafted nature of the tree. If worse comes to worse, I can fill the root area in again, but there are things I like about this look, graft or no.

 

[Emrys]

I respect your modesty Ben. Not posting images while its not at its best. I've seen this tree in person and its quite impressive regardless of a bit of reverse taper.