Japanese Black Pine

(Bill Daniels) #1

Good Morning Jonas

Do you de-candle – the same year you repot ?. Repotting a healthy JBP in the winter months.

Report in the winter dec thru Feb

De-candle in the summer June thru July

pull needles in the fall Oct thru Nov

I’m still learning --I see healthier tree the second year then repotting.
Bill D

(Jonas Dupuich) #2

I often decandle the same year I repot, but it depends on the health of the tree. If the tree is in any way weak or didn’t receive enough fertilizer in early spring, I don’t decandle.


What stage is the tree in? Development, refinement? Is it a young tree, semi-mature or mature? All this plays into the steps you will take.


I was also wondering if we are reducing the root ball of a JBP, should I also remove part of the foliage in order to balance the foliage with the root ball? I know that this is “required” for tropicals and junipers, but I am not so sure about pines.

Thank you

(Frank Corrigan) #5

No. Reducing the foliage limits the ability to repair the roots.

(Merlin) #6

I was wondering, what if you decide not to decandle and you get undesirable long shoots. What do you do with those?


If reducing the foliage reduce the roots repair ability, does this means that is better to not decandle or to leave an sacrifice branch before repotting? I know Dupuich says he decandle, but does it increase the success rate if I just do not do it? Or all the success is on the post-repotting care?


(Jonas Dupuich) #8

Not decandling doesn’t always yield long shoots. When they do, there are a number of techniques to address them. Some can be cut off, others can be shortened, and others can be left long for a year or two and cut off later. I tend to decide which approach makes the most sense branch by branch while I’m working on the tree.

(Frank Corrigan) #9

First off, there is no contradiction with the techniques and processes suggested by Jonas or myself. Jonas is always careful to explain the circumstance under which it is safe and or desireable to decandle.
Your question was related to the difference in approaching deciduous and conifer type trees in general. You specified that you were reducing the root ball and asked about removing foliage from a pine.
In conifers the energy for recovery is not stored in the roots like deciduous trees over winter. The energy comes from photosynthesis in the needles and the signal to send energy to the roots for repair comes from the hormone auxin produced in the apical buds. So the more foliage left,the more apical buds left, the more energy the better the recovery. Candles, sacrifice branches, needles, everywhere on the tree.
Hope this helps. A good guideline is to perform only one major work session on a tree per growing season. Always be sure the tree has fully recovered before considering more work. Professionals can often perform more because of the detailed care given the tree prior and post, also the diagnostic knowledge they have to gauge the strength and overall condition of the tree they are working with.

(Merlin) #10

Thank you for your reply! I’ll just wait and see what the tree does and decide what to do next.


I was very careful when I stated my question as I knew it could be misinterpreted. I did not want to say that Jonas or yourself contradict each other and if it sounds like it, I apologize. I am pretty sure that Jonas and yourself know when and what to do to any tree. More important, the pre and post care after any procedure. My question was more regarding for a novice (myself) having a larger success rate.

Now, according to your previous answer I would say that my success rate would increase if I don’t decandle the previous year as more energy is stored on the pine needles. But, I could decandle if the tree is strong and repot with the proper pre and post care.

Thank you for sharing.

(Frank Corrigan) #12

Thanks for the clarification.

If you decandle a pine at the proper time the candles will have been replaced with more buds and thus more needles than before, by the end of that growing season. So in most cases you will have a stronger healthier tree.
Please note: i did not state the energy was stored in the needles. That is not the case. It is produced by photosynthesis occurring in the needles. Repotting the following spring will not be affected because the foliage has all been replaced.
If you are considering decandling shortly after repotting then that is unwise.
Please feel free to clarify if i have misunderstood your comments.
Best in Bonsai