Japanese Black Pine Decandling and Candle Pinching

(Andy Johnson ) #1

Hi folks.

I know there are quite a few posts on his subject and I have read many but I’m still a bit confused on this subject as far as where timing is concerned. I think the books and most advice talk about date specific decandling and I think this is mainly based on US bonsai enthusiasts. Being a UK based enthusiast, I’m not sure if my climate is comparable to most in the US so equally, I’m not sure if I can decandle at the same dates that are suggested. Is there a way I can determine when to decandle based on anything else? I.e. What the shoot looks like? How long the shoot is etc?

Also, can I just shorten a candle without removing it? For example, say I’ve got two shoots next to each other of equal length, can I pinch one in half and the other in two thirds? Will this promote new buds on the ends of the remaining shoots? The idea would be to have branches of different lengths.

Many thanks,


(Jonas Dupuich) #2

Here are some tips for determining when to decandle black or red pine.

  1. Find out when people who live in your area decandle and check their results.
  2. In the northern hemisphere, decandling season runs from late May in cooler areas (like Seattle) to early July in warmer areas (the southern US). Select a time to decandle based on whether your summer is cool or warm.
  3. Decandle larger trees before smaller trees.

In general, the most common mistake relating to decandling is decandling trees that shouldn’t be decandled (too weak or too young or not enough fertilizer in spring). Missing the timing by a few weeks will result in needles that are a bit longer or a bit shorter than desired. If this happens, simply adjust the dates the following year.

The timing has little to do with how mature shoots are in spring. The important variable is how much time summer shoots have to develop (the shoots that emerge after the tree is decandled).

Pruning by shortening candles or removing large candles can be a good approach to developing pines, but these techniques are not decandling and will not achieve the same results.

Many of the basics are covered here:

I’ll be happy to clarify anything in this article if additional questions come up!

(Andy Johnson ) #3

Hi Jonas,

Many thanks for your quick reply! I think I understand a little more now but a quick additional question. You mention in your reply:

“Missing the timing by a few weeks will result in needles that are a bit longer or a bit shorter than desired. If this happens, simply adjust the dates the following year.”

So when we pinch / decandle at this time of year, is it so new buds can form this year? I assumed if we pinch / decandle this year it’s in preparation of buds forming next spring? Is this wrong? You say about needles being “a bit longer or a bit shorter than desired” - this makes me think buds will form this year and start growing and the length of growing time left this year will determine how long the needles are. Is that right?

Thanks again,


(Jonas Dupuich) #4

Strong trees are expected to produce new shoots in summer that will be fully mature by November. We’re essentially removing all of the spring growth (which is coarse) and replacing it with summer growth (which is less coarse) within a single year.

If we cut too far back (say, between the previous year’s needles) the tree will produce needle buds. These can take two years to mature. Decandling is the one technique that allows us to (theoretically) double the number of branches on the tree every year.

(Drew) #5

I live in the UK and was told by someone on an American forum to count 130 days back from my first winter frost (so working back from 1st November makes the date 25 June) then cut the weakest candles then in 10 days cut the medium strength candles then 10 days after that cut the strongest candles… OR alternatively at the 100 day mark cut them all at once using the stub method…
I did the latter (on the 7th JUNE) and the summer shoots that were produced where not that strong… I showed Peter Warren the tree when he was at our club and he asked why I cut the candles at all… he said that I cut them too late and I gathered from what he was suggesting it wasn’t a good idea to candle cut at all or if you do then do it a lot earlier! I will post the before and after pics so you can see what I’m talking about

(Andy Johnson ) #6

Hi Drew - that’s interesting. It would be good to see the pictures if you don’t mind posting them? What are you going to do this year?


(Drew) #7

So this tree was weak when I got it in sept 2015 so the only thing I did to it in 2016 was re-pot it into better soil.
In feb 2017 I pulled needles and wired it:


On 7th June 2017 I cut candles (stub method):

The summer candles were a lot smaller compared to summer 2016 as you can see from the pictures I took yesterday 23rd May 2018:


All of the candles are between 1 and 3cm long so didn’t touch it at all feb just gone (on the advise of others). The next time I plan to do anything to this will be feb 2019 when I’ll shoot pluck/select/wire again.

What are your thoughts Jonas?

(Drew) #8

So you can see the much shorter needles from last years summers shoots and the first spring candles this year are also not very impressive…

This pic was taken 25th March 2018 before the spring flush:

you cant really see how short the needles are in this pic because I didn’t pull the old needles during winter.

(Reid ) #9

That is a nice looking tree! I’d say you were on the right track. I’m no expert by any means but I would say cut the candles 1 month earlier and see what the lenght of the needles are at the end of this year. I bet they would be about right where you want them if not you will know to cut them earlier or later the next year.

(Linda Mercurio) #10

Wow that’s great, I want one too…

(Jonas Dupuich) #11

Decandling can be tricky in cooler climates. Decandling around June 7 is relatively early. If starting a week or two before that doesn’t make much difference, I’d try decandling every other year or possibly not at all.

I agree that holding off makes senes this year as the new shoots have yet to grow much.

The other factors that may be relevant are how much the tree was fertilized before it was decandled and how strong the roots were. It’s common to skip decandling the year pines are repotted, and even strong trees that didn’t receive much fertilizer in spring don’t always respond well to decandling.