Hello! I have been growing a variety of seedlings from kits I received at Xmas. Many of the seeds I planted either failed to germinate, others I dug up after months of not seeing any growth and found the seeds had sprouted but succumbed to mold that was not visible on the surface.

Now I have around 6 organic pots of little baby trees growing out of coco coir, but I'm seeing bits of mold appearing on the containers or the soil itself. I'm under the impression that you normally wouldn't want to repot trees as young as this (2-4 months), but I'm worried about the mold harming the seedlings. The weather in Seattle has just become nice enough for me to start transitioning these seedlings to outdoor life, and if repotting them into healthier soil is recommended I thought now would be the time to do it. So I have 2 questions:

1) Am I correct to repot these babies into new soil and containers to prevent harm from mold?

2) What soil is recommended for tiny seedlings like this? I have the soil mixture I often see recommended for bonsai (Akadama/Lava/Pumice), but perhaps that would be too rough for seedlings? I can also plant them in coco coir again, or general potting mix.

Thanks for your time.

(Species include: Rocky Mountain Pine, Japanese Black Pine, Norway Spruce, Royal Poinciana)

Hello, when you repot it, you don't need to use coco coir again, it's very wet when pure, that's good for germination, but not so much for later stages.
I mean, sometimes I mix some on the substrate, but I don't use it pure if not for germintation...

I made my own substrate with organic soil, rough sand, or fine gravel, sometimes pine bark...
That and the proportion of the mix depends on the species.
I don't use nothing too special for young trees, just a well draining soil, very aerated so roots can spread easily, just have in mind that the amount on organics also depends on species and climate, as it tends to stay more wet the more it has.

Seedlings need a lot of light, so I would put outside if the climate is comfortable, just on a lil bit of shade on the first days after you repot it...

Proper time for repoting is on spring, prefered early...
So you're right to repot it if the time is right.

Thanks for your input. My concern was that the akadama mix I have looks very gravel-y and course, and I didn't know if that would be too rough on fragile seedlings.

What I may do, since I have an abundance of Japanese Black Pine seedlings, is repot a few of those in different soils and see how they handle the transition.

I see no reason te repot. I would however get these outside as soon as possible.

I have two questions please guide me about this. These questions are shown below here:

1. www.bonsaiempire.com/forum/help-me/19829-please-help-to- gosloto -identify-my-bonsai?start=20

Waiting for best answer as soon as possible. I am too confused here.