My Jack pine repotted

I am quite happy for a nursery stock tree, two years in training. Was repotted first in 2016 into a bonsai pot with substrate around the nursery soil. Now it was repotted for the second time. Most of the roots had gown around the nursery soil and the Shin was quite empty. By now, about 75% of the nursery soil has been replaced by bonsai substrate. Pushing strong growth. Repotting is for me the most stressful operation with bonsai and I always find myself hoping I didn’t do any mistake… Too bad I can’t upload the video… The plan for the future is to severely cut on the extremities creating more relative height than length and asymmetry towards the left.


Rafi, it sure looks good for a nursery stock tree. I’m surprised that they sell pin gris at garden centres in Quebec. Haven’t seen any in Ontario. Marco Invernizzi likens repotting to open heart surgery. It is always stressful waiting for the patient to recover. The other major stress in cold winter areas is seeing who doesn’t wake up after winter and if they lost any appendages.

Yes, quite common - not normally the caliber of this trunk for the price I paid at the time (CAD 70). I lost two trees in my first winter here but this time, with a greenhouse has been really nice.

Rafi, how do you heat your greenhouse?

I have a standard oil heater until recently it was connected to a thermostatic cube, I guess that’s the name. It is a plug for the electricity into which you plug your appliance and it turns on at 35F and off at 45F. It is all a bit imprecise but I managed to keep between 35F and 45F (around 2C and 7C) for all winter. Now I am letting the temp rise to whatever below 20C it gets with the sun but I added a dehumidifier (at 60%) to prevent mold and add ventilation.

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So after thinking about the design and about what the extra long growth on the edges provided in the fall to the roots as well as the conservative approach that I took with the roots I felt comfortable to cut some in the extremities and bring closer to the trunk the lower right branch. It looks much nicer now. When I have time I will put another updated picture.

Rafi, is your greenhouse double walled? How do you retain the heat in Montreal winters?

it is a three season porch and I created air pockets on each window and door with transparent plastic isolation film. The rest of the year is my bonsai workshop too. I am quite happy with it but I would like to have a more spacious greenhouse.

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Thanks for the information Rafi.

Here’s a quick shot of the tree as it stands now…

moving to the horticulture category

Put it up on YouTube as “Unlisted” and share the link here.

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Here is a link to youtube. It is public.

@rafi, if you put your link on a line of it’s own, it will show as a one-box.

Edit your post and post this on a line by itself:

(I made the link bold so the forum wouldn’t one-box the link)

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I got it. thanks for the suggestion.

Rafi, thanks for adding the Youtube link. How did the tree respond to the repotting weeks later?

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It seems to be doing just fine, candles growing everywhere. Dropping pollen. I don’t seen any signs that tree skipped a single beat.

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It is great that you are getting some good experience with pinus banksiana given all of the Yama dori in the province. I find that the real test for repotted trees is the summer heat. Your own skills and greenhouse should give you an edge.


I am not worried. It is doing great. I am more interested if it may have a second flush considering that last year when it overwintered outside it took until May or June to get to the stage of growth that this year with the greenhouse I achieved already in mid March…

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It would be interesting to see if you get a second flush with a longer growing season but the second flush will come only by shoot removal, I believe. That might be risky for a specie not known for doing that. You could experiment on a branch you plan to remove.

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