Seed Starting Soil?

[LemonBonsai]

So I have some lemon seeds on the way in 100% Peat moss, I have attached a picture of them (3 weeks old). So far I have only had success with peat moss. I tried some seeds in bonsai soil but indoors it stays way to wet. I'm curious what all of you use for your seed starting soil? I have heard alot of people do good with a mix of peat and potting mix, sand, and perlite. And if you use bonsai soil for seed starting how do you keep it from getting to wet? Also how old should the sprouts be before moving them to bonsai soil? I dont want to disturb them to early but I also want them to get used to their bonsai pots and soil as soon as possible. Should I wait until they have a couple set of true leaves before moving them, or just let them grow for a year before touching them?

 

[Wires_Guy_wires]

I use whatever I have laying around.
The key to organic soils is to water them as organic soils: two or three times a week, or whenever it's dry to the core.

The only stuff I can't handle whatsoever is cocopeat. It's just never 'right'.

 

[penumbra]

The only stuff I can't handle whatsoever is cocopeat. It's just never 'right'.

It works well for me. I much prefer co co to peat.

 

[bluesky]

In November I collected about 50 acorns of Pyrenean oak and 10 English oak. I first germinated them all in humid kitchen tissues in a sealed plastic bag, and planted each one only when its root was about half an inch or more. Nearly all the acorns germinated. So many that I could experiment a bit with the soil. I put a few in 100% peat, then 20 with about 20% vermiculite 80% peat, another 20 with 50% vermiculite/peat, then about 10 with 33% vermiculite + 33% cat litter +33% peat. Finally, for my amusement I put the last Pyrenean oak in 100% vermiculite.

I also added oak root fungus to about half of each batch, from the roots of a Portuguese oak while I repotted that. To see if this makes a difference at early stage.

You know what? They're all growing well. No discernible difference between the major groups. No clear advantage of adding the mycorrhizal fungus. Although within the groups some have grown taller/faster, or bigger leaves than others, but not correlated to the factors that I imposed.

Amazingly, the 100% vermiculite is growing one of the best of all. (Maybe I should have tried a bigger batch of those.) Also interesting, this one has grown moss sooner than the others, not through anything I did intentionally.

Conclusion: the soil doesn't matter in the first year... it's more about the conditions; light, watering and fertilizer, than the soil.

They're all in full sunlight for about half the day, with watering twice a day now it's getting hot here. I'm using a cheap generic liquid fert every 10 days.

Next March or so I will repot them into larger pots in cat litter / pine bark mix. I won't use expensive bonsai soil for probably 5 or so years.

 

[Shibui]

Seed starting mix depends on the species I grow. Easy to grow seeds are just planted in whatever I have which is usually my bonsai mix which I buy pre-made in bulk. Actually cheaper than most commercial potting soils.
More delicate and difficult seeds are sown in 'seed raising mix' because it has been sterilised and has good characteristics for seed.
Watering MUST be manged according to the pot size and shape as well as mix and conditions. If it stays too wet you are watering too much.

There is no one right answer to when to pot up seedlings. Seedlings can be potted up at any time they are large enough to handle. Usually that is when they have first real leaves but I sometimes don't get around to doing them early so a few stay in seed trays for 1 or 2 years before getting a first root prune and their own pots. Age does not have any real bearing on transplant results. Younger seedlings do seem to cope with root damage/cutting far better than older trees. I regularly cut the germinating roots on oak seedlings quite short well before the leaves emerge and before they are actually planted into a pot (seed germinated in plastic bag or bucket).
I cut the roots of most seedlings intended for bonsai at first transplant to induce better lateral roots right from the start. That can be challenging at first but results will give confidence.

I also added oak root fungus to about half of each batch, from the roots of a Portuguese oak while I repotted that. To see if this makes a difference at early stage.

You know what? They're all growing well. No discernible difference between the major groups. No clear advantage of adding the mycorrhizal fungus. Although within the groups some have grown taller/faster, or bigger leaves than others, but not correlated to the factors that I imposed.

Amazingly, the 100% vermiculite is growing one of the best of all. (Maybe I should have tried a bigger batch of those.) Also interesting, this one has grown moss sooner than the others, not through anything I did intentionally.

Conclusion: the soil doesn't matter in the first year... it's more about the conditions; light, watering and fertilizer, than the soil.

They're all in full sunlight for about half the day, with watering twice a day now it's getting hot here. I'm using a cheap generic liquid fert every 10 days.

Next March or so I will repot them into larger pots in cat litter / pine bark mix. I won't use expensive bonsai soil for probably 5 or so years.

All these points agree with my experience.
Fungus is very good at getting from one pot to another. It is likely that all your pots will be colonised by now. Some seed already has the fungi on it so adding more is not required. Most trees can grow without fungal association. The fungi just helps out when conditions are poor. When nutrients are readily available the tree does not require any assistance.
Trees will grow in a wide range of soils. Not only the first year but all through life. The huge range of opinions on soil for bonsai should tell us that.
Sunlight and fert are really critical factors. Sun is antibiotic so helps protect from fungal infection. It is also critical for plant health. Give sun according to species tolerance though.
'Bonsai soil' is really only required when using shallower pots. Plants grow happily in deeper pots in all sorts of crap. Just look to the nursery industry for confirmation of that.

 

[HorseloverFat]

I’ve used straight peat for seed starting... and large-particulate non-organics.. and weird mixes in between.

What @Wires_Guy_wires said about watering organics LIKE organics is pretty much the key.

I’ve had more problems trying to start seeds in a more “bonsai-geared substrate... the roots find their way through WAY to quick... and nature will start “air pruning” the seedlings roots... the IMPORTANT ones.... air does NOT discriminate.

So uh.. keep on keepin’ on.

 

[HorseloverFat]

Seed starting mix depends on the species I grow. Easy to grow seeds are just planted in whatever I have which is usually my bonsai mix which I buy pre-made in bulk. Actually cheaper than most commercial potting soils.
More delicate and difficult seeds are sown in 'seed raising mix' because it has been sterilised and has good characteristics for seed.
Watering MUST be manged according to the pot size and shape as well as mix and conditions. If it stays too wet you are watering too much.

There is no one right answer to when to pot up seedlings. Seedlings can be potted up at any time they are large enough to handle. Usually that is when they have first real leaves but I sometimes don't get around to doing them early so a few stay in seed trays for 1 or 2 years before getting a first root prune and their own pots. Age does not have any real bearing on transplant results. Younger seedlings do seem to cope with root damage/cutting far better than older trees. I regularly cut the germinating roots on oak seedlings quite short well before the leaves emerge and before they are actually planted into a pot (seed germinated in plastic bag or bucket).
I cut the roots of most seedlings intended for bonsai at first transplant to induce better lateral roots right from the start. That can be challenging at first but results will give confidence.


All these points agree with my experience.
Fungus is very good at getting from one pot to another. It is likely that all your pots will be colonised by now. Some seed already has the fungi on it so adding more is not required. Most trees can grow without fungal association. The fungi just helps out when conditions are poor. When nutrients are readily available the tree does not require any assistance.
Trees will grow in a wide range of soils. Not only the first year but all through life. The huge range of opinions on soil for bonsai should tell us that.
Sunlight and fert are really critical factors. Sun is antibiotic so helps protect from fungal infection. It is also critical for plant health. Give sun according to species tolerance though.
'Bonsai soil' is really only required when using shallower pots. Plants grow happily in deeper pots in all sorts of crap. Just look to the nursery industry for confirmation of that.

......yours was much better than mine.

 

[LemonBonsai]

In November I collected about 50 acorns of Pyrenean oak and 10 English oak. I first germinated them all in humid kitchen tissues in a sealed plastic bag, and planted each one only when its root was about half an inch or more. Nearly all the acorns germinated. So many that I could experiment a bit with the soil. I put a few in 100% peat, then 20 with about 20% vermiculite 80% peat, another 20 with 50% vermiculite/peat, then about 10 with 33% vermiculite + 33% cat litter +33% peat. Finally, for my amusement I put the last Pyrenean oak in 100% vermiculite.

I also added oak root fungus to about half of each batch, from the roots of a Portuguese oak while I repotted that. To see if this makes a difference at early stage.

You know what? They're all growing well. No discernible difference between the major groups. No clear advantage of adding the mycorrhizal fungus. Although within the groups some have grown taller/faster, or bigger leaves than others, but not correlated to the factors that I imposed.

Amazingly, the 100% vermiculite is growing one of the best of all. (Maybe I should have tried a bigger batch of those.) Also interesting, this one has grown moss sooner than the others, not through anything I did intentionally.

Conclusion: the soil doesn't matter in the first year... it's more about the conditions; light, watering and fertilizer, than the soil.

They're all in full sunlight for about half the day, with watering twice a day now it's getting hot here. I'm using a cheap generic liquid fert every 10 days.

Next March or so I will repot them into larger pots in cat litter / pine bark mix. I won't use expensive bonsai soil for probably 5 or so years.

Interesting One question, do you start fertilizing once the true leaves come up? I have heard that I shouldn't fertilize them until that happens. I don't have a liquid fertilizer but I did buy bone meal for root development. (4 - 10 - 0)

 

[HorseloverFat]

I believe most people’s fertilizer/nutrition schedule (including when it is started) varies.

The seed that is feeding your seedling is packed with nutrients designed to “carry” your plant to “established root city” hehe (just woke up, my thoughts aren’t co-mingling correctly yet)

I personally wait about 4-5 months before using fertilizer on MY seedlings.. I have hears of BOTH more AND less.. with decent results..

I gotta wake up.. black tea and push-ups.

 

[Bonsai Nut]

For the Japanese black pine from seed contest, I used 100% peat.

 

[HorseloverFat]

For the Japanese black pine from seed contest, I used 100% peat.

Awesome!

 

[sorce]

Clay, Triple Bagged, in the Dark.



Sorce

 

[HorseloverFat]

Clay, Triple Bagged, in the Dark.

View attachment 312104

Sorce

Now THAT, my friend... is gangster!

(I feel that when YOU say that... the “er” is MOST important)

 

[Vali]

I started some oaks from acorns too. After germination, I placed one in sphagnum moss, one in peat, one in a mix of potting soil and perlite and 4-5 in pure perlite. The one in the sphagnum sprouted way ahead of the others. Only one sprouted from the perlite, a few weeks after the one in the moss. However, it outgrew the first after a while, despite being knocked over twice (as I recall) by my dogs. The one in peat is doing awfull, it sprouted but paused until about a week ago when it rachiticly started growing. It is about 1 or 2 cm high at the moment. The one in the mix of potting soil and perlite...misteriously vanished.
They were all in the same place at all times. I find it very weird that the one in perlite does so good even though a lot of the substrate floats when I water.

 

[bluesky]

Interesting One question, do you start fertilizing once the true leaves come up? I have heard that I shouldn't fertilize them until that happens. I don't have a liquid fertilizer but I did buy bone meal for root development. (4 - 10 - 0)

This year I started a few weeks after the first leaves had fully grown and hardened. I think that concurs with what @Horselover said, roughly 4 - 5 months after germination.

It's also true that the acorn carries enough nutrients to get the tree started in life, at least for the first year. But, this year I'm seeing my oak seedlings grow quicker than those of 2 years ago which I left unfertilized for their first year. That means the young tree is ready to grow faster than the nutrients from the seed alone can provide.

Probably in field soil in nature the young roots are already absorbing all the NPK they need from organic shit that's down there (excuse the language but it's partly accurate!)

Actually, now I'm wondering how much a seed contributes to carbohydrates and NPK in the young plant, and for how long. I'm gonna read up on that.

 

[bluesky]

I started some oaks from acorns too. After germination, I placed one in sphagnum moss, one in peat, one in a mix of potting soil and perlite and 4-5 in pure perlite. The one in the sphagnum sprouted way ahead of the others. Only one sprouted from the perlite, a few weeks after the one in the moss. However, it outgrew the first after a while, despite being knocked over twice (as I recall) by my dogs. The one in peat is doing awfull, it sprouted but paused until about a week ago when it rachiticly started growing. It is about 1 or 2 cm high at the moment. The one in the mix of potting soil and perlite...misteriously vanished.
They were all in the same place at all times. I find it very weird that the one in perlite does so good even though a lot of the substrate floats when I water.

I also tried sphagnum in about 10 of the pots with high peat content. And shortly after I took them out of the incubator/propagator and onto the garden patio, the blackbirds had a field day. They attacked all the pots with sphaggy in them. How did they know? I don't know. But since then I have doubled down on the bird repellents. It also made it impossible for me to tell how successful the sphagnum was because all those pots were left with their tender roots exposed for half a day, and a few died while others are just recovering now. Second conclusion: protect all your pots that have any chance of lavae or grubs in them. This is the other reason I'm using chemical fert this year and not organic.

Interesting that the shoots in pure perlite and in my case vermiculite did so well in the first few months. I guess it's because of the gaps between the granules bringing more oxygen-rich water to the roots. The same principle as for akadama and other granular soil.

 

[erich_raudebaugh]

I've tried an informal experiment with Japanese maple seeds this year, due to the soil I had laying around. I had a little Boon mix left and a little pumice before I bought more of everything for the repotting season.

Some are in the ground and not growing that well. They are planted in loamy garden soil. (Maybe a couple dozen? Also some died off quickly after sprouting)

Some are in composted bark and the damp conditions killed about half while the rest are growing slowly. In retrospect I should have screened the soil... I rarely water these but it's been raining a lot this year.

Some are in pure pumice and growing nicely.

The ones growing the best are in some Boon mix that I had in a bucket. They are planted in a shallow mica drum pot, it's shallow-ness probably helps because the soil dries out better.

Everything gets about 1/2 shade and 1/2 sun during daylight hours.

My conclusion is to use small/shallow pots so the roots dry the soil out. That way more oxygen gets into the soil promoting root growth. If you live in a dryer area this might not be a big deal.
Also the seeds germinated outdoors, which maple seeds seem to prefer.