White Pine Stratification

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Hey all

So I've purchased some JWP seeds from Sheffield and they arrived today. I have looked everywhere and found so many different answers on stratifying them. Looked up the info found on Prof Deno's paper on germination techniques, other articles I could dig up on google scholar on the topic and generally anything I could find out online. There has been everything from a 30 day cold, a 60 day cold -> 60 day warm and vice versa, some say no stratification at all (this seems bogus to me), and so many other claims.

In my book the best teacher is experience, except I have none with JWP haha. Anyone who has attempted JWP from seed and succeeded care to share their methods with me?

Thanks in advance friends!
 

0soyoung

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Too bad you didn't just look in the BNut Resources - Deno's book as well as the two supplements are right here!

The standard ritual is 6 weeks in the frig. Then remove the packet into the room for 5 to 7 days. Ungerminated seeds go back into the frig for another 3 or 4 weeks. Ad nauseum or until all seeds have germinated. There is no harm to keeping them in the frig longer, should you wish.

If you are unhappy with the results this time around, dusting with GA3 is the next leg up.

Stewartia pseudocamellia is renowned for supposedly needing cold then warm stratification, but dusting with GA3 and keeping the in the frig for 12 months yields near 100% germination. IOW, I don't think you need to get lost in the weeds of cold/warm/cold stratification strategies.
 

River's Edge

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Hey all

So I've purchased some JWP seeds from Sheffield and they arrived today. I have looked everywhere and found so many different answers on stratifying them. Looked up the info found on Prof Deno's paper on germination techniques, other articles I could dig up on google scholar on the topic and generally anything I could find out online. There has been everything from a 30 day cold, a 60 day cold -> 60 day warm and vice versa, some say no stratification at all (this seems bogus to me), and so many other claims.

In my book the best teacher is experience, except I have none with JWP haha. Anyone who has attempted JWP from seed and succeeded care to share their methods with me?

Thanks in advance friends!
I have always followed the directions provided by Sheffields in every order, they have been consistently correct. They always indicate the collection time and location which also gives you good information to compare to research information on fresh versus older stored seed.
 

Shibui

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I've only tried JWP once.
No stratification yielded no germination, even with some sub freezing nights while the seeds were in trays outside, so that's probably not a very useful strategy.
I did get reasonable germination by cracking the outer seed coats and planting the kernals or just the partly cracked seeds (no other seed treatment) so maybe stratification helps to crack that tough outer shell to allow water to reach the seed within.
Just offering this observation as another possible strategy for JWP seed.
 
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I didn't go with the no stratification approach. I ended up having 35 seeds that sank so I divided them into 3 batches and they all went into the fridge. I'll peak at them every once in a while, especially since I have other seeds in there that have been stratifying since January!

I figure I'll pull one bag in about 30 days and see what's happened if anything and go from there
 

Leo in N E Illinois

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I've germinated quite a few species of trees from seed. I almost always followed Sheffield's recommendations and have usually had pretty good success. Some trees like Japanese maple and Japanese white pine have a mixed strategy. Fresh seed that is still above a certain percentage moisture (I vaguely remember 60%, but could be wrong on the number) may have a small percentage of seed germinate immediately . Then if cold stratified will germinate another significant percentage. But there will be some percentage that won't germinate, these will need a warm stratification followed by a second cold stratification. With JM and JWP, the when the seed is allowed to dry below the critical moisture content, the % germinating immediately drops to near zero. The % requiring both warm and cold stratification rises sharply. This strategy of some germinating immediately, some the following spring and some the second spring is fairly common. This way the trees are not relying on ''good weather just that year'' for seedlings to survive. This strategy keeps a reservoir of viable seed in the ground for a couple years, should fire, drought, or other vagaries kill off one season's seedlings. So staggered germination is pretty common.

Second note. Seed of JWP and most members of subgenus Strobus, including southwestern white pines and others, the seed does not have a long shelf life when stored dry and cool. 18 month to 2 years in the refrigerator, dry and cool, and beyond that viability will drop below 50%. It won't drop to absolute zero for a few more years, but it is a much shorter shelf life than the 2 needle pines like Japanese black pine, where the dry seed will be viable for 10 years or more if stored dry and cool.
 

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