Propagating pinus parviflora

[Dermot]

Hi all.

Apologies, I searched the forum for this one but couldn't find a general consensus.

I picked up some pinus parviflora seeds online a few weeks ago. They're in the fridge in the sealed bag they came in at the moment.

What is the best method for germinating these? Some say take them out to room temperature for a week, into a damp sterile mix for 60days, then into fridge for 90 days. Others say damp mix in fridge for 30 days.

The seeds were hard to come by so want to try give them the best chance. I don't want them germinating too early either.

Thanks in advance!

 

[JeffS73]

I had 100 seeds, fridge for 60 days in damp moss, then into try of perlite under cover & lights. 3 germinated, the rest rotted, so either in the fridge or my germination culture were off, keeping things too wet. I've had no problem with JBP and lots of others, but, like cedar, p.parv have been difficult for me. I would try a few in a tray of pumice / sphagnum moss outdoors but protected from rain, like in a cold greenhouse.

 

[Potawatomi13]

Skip refrig, use finest grade pumice 1/16"-1/8", no moss, put outdoors wait for Spring.

 

[Shibui]

Is the seed still in the shells?
Last and only time I hade P. parviflora seed I got zero germination from seed just sown in trays but got some germination from seed where I cracked the nuts before sowing. Both lots left outdoors over winter with night temps down to -4C. Stratifying may help crack the nut to allow moisture into the seed so it can germinate???? but may need to be colder than my -4C???

Whenever I'm not sure I try to mimic natural conditions. White pines are mountain trees in Japan. Seed drops to the ground in Fall then sits under snow for winter and germinates when the snow melts in spring. This equates to damp stratification for 2-3 months. Fridge in warmer climates but outdoors in cooler areas has always been better for me. Seems to have less problems with mould, etc. Just make sure seed trays are protected from seed eaters - birds, mice, rats, squirrels, etc. Outdoors should also have more natural variation in temps that may help with germination of difficult species.

 

[Potawatomi13]

Is the seed still in the shells?
Last and only time I hade P. parviflora seed I got zero germination from seed just sown in trays but got some germination from seed where I cracked the nuts before sowing. Both lots left outdoors over winter with night temps down to -4C. Stratifying may help crack the nut to allow moisture into the seed so it can germinate???? but may need to be colder than my -4C???

Whenever I'm not sure I try to mimic natural conditions. White pines are mountain trees in Japan. Seed drops to the ground in Fall then sits under snow for winter and germinates when the snow melts in spring. This equates to damp stratification for 2-3 months. Fridge in warmer climates but outdoors in cooler areas has always been better for me. Seems to have less problems with mould, etc. Just make sure seed trays are protected from seed eaters - birds, mice, rats, squirrels, etc. Outdoors should also have more natural variation in temps that may help with germination of difficult species.

Many varieties western, Rockies white pines grow from cones buried by squirrels & birds. Whitebarks depend on this for survival. JWP very similar tree and believe this method works.

 

[Dermot]

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Seed is still in the shell. In Ireland, we tend to have quite mild winters usually. It can cycle between cooler and warmer weeks also. Typically very wet. Not sure if it's the best conditions for natural stratification. These tree's are not native to this climate!

 

[Potawatomi13]

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Seed is still in the shell. In Ireland, we tend to have quite mild winters usually. It can cycle between cooler and warmer weeks also. Typically very wet. Not sure if it's the best conditions for natural stratification. These tree's are not native to this climate!

Maybe good point.

 

[Canada Bonsai]

These 2 documents might be helpful. If you want to really optimize things, it will help to know where your seed came from. I have 4 varieties of JWP seed from different regions of Japan, and their timing and success rate vary significantly. Also, success rates of JWP seed vary significantly which is something that harvesters and brokers often point out when selling seed.

This year, in China, the higher quality JWP seed is going for $3-4/seed, but even with this higher quality seed one can often see success rates below 30%. For the last 2-3 years I purchase my JWP seed exclusively from Japan and I am seeing success rates that are consistently above 80%, which in part has to do with the fact that my harvesters are testing the seed in advance and selling only those that look good.

All this to say that if your seed does not work, user-error may not be the problem -- there's a lot of unreliable JWP seed out there.

Canada Bonsai Propagation Schedule

This schedule should be used as no more than a rough estimate! Above all, I use it to help me plan ahead in terms of substrate and space. CLICK HERE for Canada Bonsai Propagation Schedule

canada-bonsai.myshopify.com

Seed Stratification

CLICK HERE for Seed Stratification document

canada-bonsai.myshopify.com

 

[Dermot]

These 2 documents might be helpful. If you want to really optimize things, it will help to know where your seed came from. I have 4 varieties of JWP seed from different regions of Japan, and their timing and success rate vary significantly. Also, success rates of JWP seed vary significantly which is something that harvesters and brokers often point out when selling seed.

This year, in China, the higher quality JWP seed is going for $3-4/seed, but even with this higher quality seed one can often see success rates below 30%. For the last 2-3 years I purchase my JWP seed exclusively from Japan and I am seeing success rates that are consistently above 80%, which in part has to do with the fact that my harvesters are testing the seed in advance and selling only those that look good.

All this to say that if your seed does not work, user-error may not be the problem -- there's a lot of unreliable JWP seed out there.

Canada Bonsai Propagation Schedule

This schedule should be used as no more than a rough estimate! Above all, I use it to help me plan ahead in terms of substrate and space. CLICK HERE for Canada Bonsai Propagation Schedule

canada-bonsai.myshopify.com

Seed Stratification

CLICK HERE for Seed Stratification document

canada-bonsai.myshopify.com

Thanks very much for going to the trouble to post the documents. Excellent information there.
Yes I'm sure seed viability is the biggest issue. It's crazy the seeds are so hard to come by! I have a pinus parviflora in the garden and it's got a small few cones forming. They must be very tasty - they were like bullseye's for larvae this year! Do you know how long they take to fully develop?

 

[Shibui]

Most pines take around 18 months to mature seed. That one in the pic is now 6 months from the spring 'flowering'. Expect it to mature next autumn. Cones mature and open late summer or autumn.
The best seeds drop the day the cone opens so bagging is a useful tool to make sure the cone gets as ripe as possible but you don't lose valuable seed because you forgot to check.

 

[MichaelS]

I've grown quite a few. After soaking in hot water, I put them in the fridge (4C) in BARELY moist, sterile (new) vermiculite (this is VITAL! You just want to be able to feel a little moisture and that's all) for 3 months (2 months is probably ok) in a clean plastic pot then in a in a plastic bag with a few holes poked into it.
Sow in squat terra cotta pots 2-3cm apart and 1.5cm deep in a medium consisting of 3-5mm particles of quartz sand/gravel and orchid seedling bark 70/30 and include to 1/3 of the depth an aeration layer of coarser particles (10mm, then 7mm, then your mix) Rub in some healthy mychorrizae from a healthy tree at the time of mixing. Water once then leave them until the mix is rather dryish then soak again. Do not repot for at least 1 year after germination. You can also mulch the top with some pulverized sphagnum moss to a few mm after sowing. This is said to inhibit damping off as the seedling emerges.

 

[Diggumsmack2]

I've always wondered why some seeds are hollow, just empty shells. I've got an austrian pine that produces 90% empty seeds if not more. Also a 25 year old pinus mugo which produces 100% empty seeds as far as I can tell, never found a viable seed on that one.


From my experience, the whitish seeds are empty, the darker ones are viable, just from cracking them open to check. But I know on JWP this is not the case, the dark color one can be blanks.

Why would a tree produce 100% unviable seeds?

 

[Shibui]

Why would a tree produce 100% unviable seeds?

Pollination problem is the most likely cause of empty seeds. I've found the same with many of my potted pines but the trees in the garden produce viable seed. Male pollen cones are usually below the female flowers on pines and pines are wind pollinated so pollen from male cones needs to be blown over to receptive female cones. In a mountain forest that works well and I guess it is an adaptation to reduce inbreeding but can reduce seed set in isolated trees.
In isolated, potted trees you can try artificial pollination. Take a pot with male cones releasing pollen close to the emerging female cones and shake the branch to release pollen onto the female part. Doing that each day for a week while the cones are releasing pollen should give much better pollination and therefore viable seed.
Many species go through the seed production cycle even when there's no embryos and pines seem to be one of those. There's even a botanical term for that but I can't be bothered searching now. Other species have adapted so they don't waster energy creating fruit if there's no viable seeds to mature and spread around. Apples, for instance, drop off the tree if there's no viable seeds.

In JBP lighter colored seeds are definitely empty but I have had so little experience with white pines so can't comment on color as a guide to viability for them but will take your word that lighter does not mean empty.

 

[Diggumsmack2]

In JBP lighter colored seeds are definitely empty but I have had so little experience with white pines so can't comment on color as a guide to viability for them but will take your word that lighter does not mean empty.

Here's a bucket o seeds from JWP I collected over the weekend, I've cracked open probably a dozen and found no viable seed inside so far. Mostly all are dark in color.

 

[Dermot]

Thanks for all the replies. Much appreciated.
Im not convinced that in my climate with no greenhouse available that outside natural stratification is the best route. After all I've read across the net over the last few weeks, the below is what I'm going with.

- Yesterday I took the seeds out of cold storage and let them come up to room temperature for 24 hours.
- This evening I put the 30 seeds into warm/hot water. After 2 hours 10 were left floating.
- After 20(ish) hours, I will pop them into a mix of 3%hyrogen peroxide.
- I grated some fresh sphagnum moss earlier, popped it into a bag and sprayed a mix of rain water with a tiny bit of seaweed extract over it.
- I will pop the seeds into this sphagnum and store in sealed lunchox at room temperature for approximately 90 days.
- Then into fridge for 60 days.

If anyone has any last minute advice, please speak now or forever hold your peace

 

[Dermot]

Seeds in warm water this evening!

 

[MichaelS]

Thanks for all the replies. Much appreciated.
Im not convinced that in my climate with no greenhouse available that outside natural stratification is the best route. After all I've read across the net over the last few weeks, the below is what I'm going with.

- Yesterday I took the seeds out of cold storage and let them come up to room temperature for 24 hours.
- This evening I put the 30 seeds into warm/hot water. After 2 hours 10 were left floating.
- After 20(ish) hours, I will pop them into a mix of 3%hyrogen peroxide.
- I grated some fresh sphagnum moss earlier, popped it into a bag and sprayed a mix of rain water with a tiny bit of seaweed extract over it.
- I will pop the seeds into this sphagnum and store in sealed lunchox at room temperature for approximately 90 days.
- Then into fridge for 60 days.

If anyone has any last minute advice, please speak now or forever hold your peace

Don't think the seaweed is a good idea. Might set up a mold in time because it will have amino acids in it. I would re-do without that. Also, don't keep them completely sealed for 3 moths. They still need to breathe.

 

[Dermot]

Don't think the seaweed is a good idea. Might set up a mold in time because it will have amino acids in it. I would re-do without that. Also, don't keep them completely sealed for 3 moths. They still need to breathe.

Thanks Mike. That did cross my mind too. I'm hoping the sphagnum will help keep mould at bay