Some 2020 JBP Seedlings

Hi, I just wanted to share some progress on seedlings I started this year around January. All thanks to Jonas’s inspiration, it’s been a great start to my Bonsai journey!

I started seeds indoors, under grow lights, following the advice here about seedling cuttings:

It was touch and go what with damping off and humidity issues, but eventually, I got a good number of successful cuttings. It was of the order of 200 seeds, 150 germinated, 100 made it to cuttings, and I’ve now got about 60 healthy plants.

Here are a few as they are this Autumn. Most got really long needles in their first flush. Many then got a second flush, with shorter needles. Many of them have a lot of shoots really low down, some 7 or 8, these have stayed quite squat. Some got taller, and have large buds low down, so there’s quite a lot of variation.

I wired a couple early on after the first flush. This provoked a strong fattening response:

I’m using liquid feed without Nitrogen, and the rooting tells me I will be repotting in Spring:
20201102_145345|666x500 !


Wow, these are looking great! I’m curious - what’s the idea behind using fertilizer without nitrogen?

I also wondered if you knew why the long, scraggly needles appeared on some of the trees - this isn’t something I see on pines growing outdoors.

cool project. the extremely long needles is weird.

Thanks, I’m really enjoying the whole process, the gratifying results are a bonus. The large number of low shoots are giving me pause for thought regarding design though.

The long needles are odd aren’t they! At first I thought I’d got Pinus Wallichiana by mistake. About half of the saplings grew out this way. These are what I’m calling the second flush needles. In order they went cotyledon, first flush (short needles), seedlings cut, second flush (half saplings v long needles), third flush (all normal / shortish - end of summer).

I’m guessing it’s either something to do with the indoor environment - 18hrs of light, fan for ventilation and constant mild temperatures (21c / 70f), or a response to the root hormones, a mix of NAA and IBA. I’ve noticed IBA can force Larch shoots to extend hugely / unnaturally.

The fertiliser without nitrogen is (perhaps wrongly) what I have read as being more suitable after the summer solstice, thru Autumn/Fall. My assumption was to stop the tree from pushing new growth that won’t have time to harden off before dormancy. However, I have heard conflicting views on this. From Spring to summer solstice I’m using feed with nitrogen. I’m in the UK, USDA Zone 8b.

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I have yet to use fertilizer without nitrogen. Michael Hagedorn has a good discussion of the topic in his new book, Bonsai Heresy.