JBP seeds

[bonsai-max]

Hi, I made an experiment with JBP seeds, not so many just 30. I put yesterday in full perlite after a stratification period. Now th temperature are still cold but no under 0° so I will put outside, not in full sun ( i don't know if is a good idea). Just a question regarding fertilizer, when you start to feed the plants ? I have several fertilizer, miracle gro, Biogold, special bonsai liquid, plus humic acid. When I have to start and the dosage ?

 

[bdmatt]

I start feeding jbp seedlings after they start elongating. So basically, after about a couple of centimeters of initial growth or right before they drop their seeds. In terms of time, 2/3 weeks after they start sprouting.

Start with very little fertilizer at first, maybe a piece of biogold for every 5 square cm. Then build up the dosage as they progress. For about 30 seedlings, 3-4 pieces of biogold is more than enough. You can also use other fertilizers, just keep the dosage low since seedlings really don't require much.

Here's some photos so you get the idea of when and how much fertilizer:


This photo is a batch of pines I started for this year. I plan to start fertilizing in a week:



You can also read up on the 6 year JBP challenge thread, lots of information on growing from seeds there.

 

[bonsai-max]

Ok, will do it.
So direct sun yes or not? the seed bed have also a platic cover
That's the situation:

 

[bdmatt]

I put mine in direct sunlight. They germinate faster that way. I've grown them in indirect sunlight as well, took a week or 2 longer to germinate.

 

[Srt8madness]

I germ mine under a grow light, but sun will obviously work. Seeds don't need fertilizer, they've got alllll the energy they need in the seed. When they put on true leaves (needles) you can fertilize.

 

[Shibui]

Full sun is best but, like all other plants, you will need to maintain moisture for the seedlings. Small containers with free draining soil dry very quick on warm days and young seedlings have very little stores or resilience. If in doubt, some afternoon shade may help maintain moisture levels until the seedlings are stronger or you can up-pot into larger containers.

Agree with @bdmatt on fert. Any time after germination is OK for fertilizer.

 

[bonsai-max]

Hi there, some seeds are growing now, so it's time to start fertilize.
Do you use a normal dosage or half dosage ? Kelp extract ? It's in pure perlite so I think he really needs food

Miracle grow ? Half block of bio gold ? 20-20-20 crystal?
I prefer liquid as the box as a self watering system from the bottom to keep always the perlite wet, so no water from the top.



And what are the next steps ? I have no idea. Should I keep the new plants in this growing box until the next spring or I have to move to another pot ? when ?

 

[Srt8madness]

Edit: nvm I just said the same as I did before, forgot I posted it.

 

[bonsai-max]

so these one are not the true leaves ?

 

[Shibui]

Your seedling is just showing seed leaves now. The shoot will emerge from the centre and grow with different (juvenile) leaves along the stem as it grows.
Definitely start fertilizing as there's no nutrient in the perlite. Seeds have a reserve of nutrients from the seed to get started with but that won't keep them going for more than a week or so. Start out with half strength fert but can build up to full strength pretty quick. Kelp extract is not promoted as a real fertilizer as it can have variable amounts of nutrient. No problem with using some but also rely on a more 'balanced' fertilizer with all the nutrients. Any soluble (liquid) fertilizer will provide nutrients for your seedlings. They can't read the packet so will not care what brand it is.

And what are the next steps ? I have no idea. Should I keep the new plants in this growing box until the next spring or I have to move to another pot ? when ?

Everyone has their own way so you will find many different suggestions. I prefer to prick out seedlings from this stage to a few weeks older, cut the taproot to promote more laterals for future nebari and get them into pots with real potting soil. They will grow and develop much quicker with a little root space and better soil/nutrition.
Other growers let the roots fill those little pots then lift the root ball out and pot on into larger pots because they are scared of touching roots but that leaves lateral root growth up to the plant so root formation will vary.
You will also find references to seedling cuttings where growers chop the entire root off seedlings around this stage of growth then strike the tops as tiny cuttings. many claim great results but I get very similar results just by pinching the tap root at transplant.

All that means the next steps are up to you. All approaches seem to give good results.