How long do you cold stratify Japanese Black Pine?

[WIlliam_Butler_Yeets]

Hey folks, I got a couple packets of seeds over the weekend, JBP, and Shore Pine (contorta v contorta). They were soaked for 24 hours (separate cups) and the floaters were planted up just to see if anything happens while the sinkers went into the fridge in some moist moss. I've read a bit about JBP from seed and have seen cold stratifications times usually in the range of 30-60 days, however, on Bonsai Tonight, Jonas says he just leaves them in the fridge for a week before sowing? It's getting to be about germination time here in the Willamette Valley, and while I want some healthy seedlings (I definitely waited too long to order seeds), I'd like to also get the highest ratio of seed:trees that I can. Any experience to share with shorter stratification periods?

 

[Dav4]

I seem to remember when I started JBP seeds every spring, a 1 week cold stratification period would suffice, and I've heard that they germinate well without any cold treatment .

 

[WIlliam_Butler_Yeets]

I seem to remember when I started JBP seeds every spring, a 1 week cold stratification period would suffice, and I've heard that they germinate well without any cold treatment .

Sounds cool to me, I'd much rather be germinating in April rather than nearly-June

 

[Shibui]

I've certainly had good germination of JBP seed without any stratification. Just sow in trays/pots when the weather seems warm enough and wait for them to shoot.
Alternative is to sow in trays outdoors and let nature take it's course. The seeds seem to know when it's the correct time to germinate and JBP seedlings can cope with light frost.

Make sure your seed trays are protected from seed eaters. You seem to have quite a range of critters over there that make a living by finding buried seeds to eat.

 

[RoadManDenDron]

I have also had good success without germination

Though i did notice the seeds came out closer to the same time as each other with stratification

While the un-stratted were very sporadic

 

[WIlliam_Butler_Yeets]

I've certainly had good germination of JBP seed without any stratification. Just sow in trays/pots when the weather seems warm enough and wait for them to shoot.
Alternative is to sow in trays outdoors and let nature take it's course. The seeds seem to know when it's the correct time to germinate and JBP seedlings can cope with light frost.

Make sure your seed trays are protected from seed eaters. You seem to have quite a range of critters over there that make a living by finding buried seeds to eat.

Yes, the plan is putting all the seedling pots in a flat and attaching some window screening over the top until the little trees are a bit established, lots of little seed-eating birds around and squirrels that love to dig in anything

 

[River's Edge]

Hey folks, I got a couple packets of seeds over the weekend, JBP, and Shore Pine (contorta v contorta). They were soaked for 24 hours (separate cups) and the floaters were planted up just to see if anything happens while the sinkers went into the fridge in some moist moss. I've read a bit about JBP from seed and have seen cold stratifications times usually in the range of 30-60 days, however, on Bonsai Tonight, Jonas says he just leaves them in the fridge for a week before sowing? It's getting to be about germination time here in the Willamette Valley, and while I want some healthy seedlings (I definitely waited too long to order seeds), I'd like to also get the highest ratio of seed:trees that I can. Any experience to share with shorter stratification periods?

I have always used a short period of time in the fridge. 7-10 days after soaking the seeds in warm water and let soak over night. There are circumstances where a higher germination rate will be achieved with longer cold stratification. It helps to know how the seeds were stored after collection in the fall ( usual time). Also if they were collected several years ago. If they have been stored in the fridge they may have dried out more and that can affect the germination rate. If you do not have access to the information on storage or collection time I would simply soak, and plant.

 

[WIlliam_Butler_Yeets]

I have always used a short period of time in the fridge. 7-10 days after soaking the seeds in warm water and let soak over night. There are circumstances where a higher germination rate will be achieved with longer cold stratification. It helps to know how the seeds were stored after collection in the fall ( usual time). Also if they were collected several years ago. If they have been stored in the fridge they may have dried out more and that can affect the germination rate. If you do not have access to the information on storage or collection time I would simply soak, and plant.

They're fresh in terms of seeds, collected in October 2024 per the packet from Sheffield's, I don't know exactly how they store them but I assume it must be generally sufficient based on the reviews I've seen on bnut of the company

 

[River's Edge]

They're fresh in terms of seeds, collected in October 2024 per the packet from Sheffield's, I don't know exactly how they store them but I assume it must be generally sufficient based on the reviews I've seen on bnut of the company

Great news, plant them!

 

[Wulfskaar]

I've had a nearly 100% success rate without stratification with JBP... with fresh seeds. Just soak in water for a day and sow.

I've had old seeds (2+ years) with very poor success rate. Not sure if stratification would have helped.