Pine from seeds

[TGBentsze]

Hi guys! I have a quick question, I recently harvested some Scot's pine seeds (in late january of 24), do they still need cold stratification?
There were out in the frost and cold for at least 2 months.

 

[Nybonsai12]

Scots pine typically require about 90 days cold stratification. are you able to keep them out in the cold until they sprout naturally?

 

[TGBentsze]

Scots pine typically require about 90 days cold stratification. are you able to keep them out in the cold until they sprout naturally?

Yes, i planted them, and they are still outside, i was just wondering

 

[Shibui]

There were out in the frost and cold for at least 2 months.

Not clear what this means. Do you mean the cones holding seeds were out in frost or are you telling us the seeds were planted 2 months ago?
I don't think dry and cold counts toward stratification. If the seeds are still in the cones they are dry and protected. Seeds need to be damp and cold for stratification to be effective.

Not sure about Scots pine but I've found that JBP does not need stratification even though it is routinely recommended. The vast majority germinate even if sown after frost so while stratified seed germinates well it is not necessary. Scots pine comes from cooler regions so may behave differently.
It would be interesting to see some germination trials with and without stratification with other Pinus species.

 

[Potawatomi13]

Just make sure to protect seed from birds,squirrels etc. also when dryer weather comes do not allow to dry out. Otherwise not worries.

 

[TGBentsze]

Not clear what this means. Do you mean the cones holding seeds were out in frost or are you telling us the seeds were planted 2 months ago?
I don't think dry and cold counts toward stratification. If the seeds are still in the cones they are dry and protected. Seeds need to be damp and cold for stratification to be effective.

Not sure about Scots pine but I've found that JBP does not need stratification even though it is routinely recommended. The vast majority germinate even if sown after frost so while stratified seed germinates well it is not necessary. Scots pine comes from cooler regions so may behave differently.
It would be interesting to see some germination trials with and without stratification with other Pinus species.

So, to be clear, they were outside, in the cones, on the tree. I harvested them around the 22 of January 2024. I let them soak for a day (and a half) in my greenhouse(around 3-7 °C winter [so the roots wont freeze]).

First I planted the ones, from the bottom, but soon after I planted the floaters as well, cuz why not.
I put them outside, not sheltered, but elevated, so they wont freeze.

Here are we now

They said scots pine needs at least 30, but 60 days is better of cold stratification. The seeds will sprout without that, but the lings will be so so weak, and I need strong one, because I want to cut them for better bonsai potential.

I was just wondering if being outside in cones count as cold stratification.

 

[Shibui]

I was just wondering if being outside in cones count as cold stratification.

This is what I guessed you were getting at. Outside in cones probably does not count in the stratification timing because the seeds are dry inside the cones.

They said scots pine needs at least 30, but 60 days is better of cold stratification. The seeds will sprout without that, but the lings will be so so weak

This is the first time I have heard of weak seedlings because of less stratification. Generally the claim is you get lower germination rates so less seedlings rather than weaker. Seedling strength comes from the seed itself combined with growing conditions after germination. As mentioned, my experience is with JBP and I have seen no evidence of weaker seedlings without stratification.
In any event, stratification won't hurt.

I put them outside, not sheltered, but elevated, so they wont freeze.

Freezing does not hurt seeds before germination. Not sure how cold it gets at your place but light frosts do not seem to bother pines during and after germination either. I guess there's a temp that could be fatal but the natural inhibiters in the seeds are generally pretty good at not allowing germination until after the worst cold has passed.
My JBP seeds are left outside through winter and germinate as spring arrives. They have occasionally survived late frost but probably not frozen soil as it doesn't get that cold here by the time the seeds start growing.

Take note of the warning from @Potawatomi13 Mice and birds are very good at finding seed, even buried in pots. I have lost entire plantings over 2 or 3 nights if a mouse finds the pot and can get in. Seed pots should be covered with mesh to be mouse proof.

Look forward to seeing the results when your pines start coming up. That's always a great feeling.

 

[Wires_Guy_wires]

Scots pines don't require stratification.
So all the sinkers should be good to go.

 

[stewarjm192]

I put them outside, not sheltered, but elevated, so they wont freeze.

What do you mean by elevated? If you mean lifted up off the ground, you almost certainly are lowering the temperature these seeds will feel, compared to sitting on the ground. The ground will mitigate temperature fluctuation, when things are up on benches, and air can circulate on all sides of your seedling vessel, the temperature will drop........pots on benches freeze, while pots on the ground stay thawed

 

[Shibui]

What do you mean by elevated? If you mean lifted up off the ground, you almost certainly are lowering the temperature these seeds will feel, compared to sitting on the ground. The ground will mitigate temperature fluctuation, when things are up on benches, and air can circulate on all sides of your seedling vessel, the temperature will drop........pots on benches freeze, while pots on the ground stay thawed

I suspect this depends on how cold it gets and for how long.
Down here cold accumulates at ground level so higher is warmer. It is well known that if we can get sensitive trees planted in the ground through the first winter they are generally above frost level and safer in subsequent years. Ground never freezes in my area so that may account for the difference.

 

[TGBentsze]

What do you mean by elevated? If you mean lifted up off the ground, you almost certainly are lowering the temperature these seeds will feel, compared to sitting on the ground. The ground will mitigate temperature fluctuation, when things are up on benches, and air can circulate on all sides of your seedling vessel, the temperature will drop........pots on benches freeze, while pots on the ground stay thawed

Soo, my "greenhouse", a 5m x 1m with a height of 1.5m is eleved, so when it is summer, i can just take all the panels off, and have it as a table.

I have a small shelf right underneath of table, for pots etc. and thats where the seeds are planted in pots.

 

[TGBentsze]

I suspect this depends on how cold it gets and for how long.
Down here cold accumulates at ground level so higher is warmer. It is well known that if we can get sensitive trees planted in the ground through the first winter they are generally above frost level and safer in subsequent years. Ground never freezes in my area so that may account for the difference.

In my area, ground tend to freeze, mainly in hard winters (like this one at us)

 

[stewarjm192]

In my area, ground tend to freeze, mainly in hard winters (like this one at us)

if this is the case, your seedlings should be on the ground, they are only going to freeze harder, and faster elevated off the ground......keep them on the ground, better yet, place a heat mat under them