The best time to thin pine bonsai is between late fall and early spring. I didn’t get to the red pine forest below until early April this year. Because I was working on the tree late in the season, I kept the work simple. I cut back each branch to two shoots, removed old needles, and shortened some of the longer candles. I decided against wiring the tree to avoid damaging the new candles.
Red pine forest – April 2011
Shortening candles is a simple technique to weaken vigorous shoots. Letting long candles like the one pictured below puts a lot of energy into the branch, usually at the expense of weaker branches. I shortened the longest shoots to make them roughly even in size with the weaker candles. To avoid damaging the emerging needles, I broke the candles with my fingers.
I also cut back last year’s growth to two shoots per branch. As the pines in this forest are fairly vigorous, I found a lot of branches with three or more shoots per branch. Thinning to two shoots per branch helps me balance growth while creating good branch structure.
Cutting back to two shoots
Extra bud removed
I removed all two-year old needles and some of last year’s needles.
First and second-year needles
Second year needles removed
As sap built up on my tweezers, I cleaned them with a steel bristle brush.
Thinning and removing extra needles gets me in good shape for next month’s decandling.
After reducing the vigorous candles and removing old needles and extraneous shoots, I noticed that the foliage is still a bit dense. I’ll likely remove more needles at decandling time in mid- to late June. And if I can find the time, I may also wire the tree as I have yet to completely wire the forest since its creation a couple of years ago.
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Daniel Dolan says
Your instructive discussions of Bonsai training and development are excellent. Though I appreciate Walter Pall greatly, seeing another photo of a 75-100 year old collected tree that is “coming along nicely” is overwhelming for some.
Question: I grasp much of what is required for pine care….but after one reduces the length of candles in the medium and high strength areas…..why would you “de-candle’?
Hi Daniel – good question. Shortening candles in spring is a good way to weaken the stronger areas of the tree. Decandling can also strengthen weak shoots and weaken strong shoots. Beyond that, decandling can increase the number of buds per shoot and shorten needle length. This year I’m shortening candles in spring to slow down the really strong areas. When I decandle the trees in June, I’ll remove needles from these branches which will further weaken the strong shoots. For every strong shoot that I decandle, I can expect two or more summer shoots. These are the best benefits of decandling – it greatly speeds up development time and it keeps strong growth in check.
Why shorten the long candles now and decandle later? If I removed the entire candle in early spring, the new shoots would have a very long time to mature, roughly from April through November. By decandling in June, the summer shoots have less time to develop, thereby keeping growth in check.