Seed Prep

[Owen Reich]

This is the time of year I sow seeds in Nashville. Generally speaking, the book Dirr's Manual of Woody Lanscape Plant Propagation is a relaible resource for seed prep; stratification and scarification to be exact. Asexual propagation techniques are excellent.

This post is about a little trick to increase germination rates (for the seeds that are viable). The seeds in photos are Pinus bungeana from Schumacher Seed and Pinus parviflora from a questionable Chinese source. Some of the seed packets were not even pine . A few thick seedcoat tropicals as well.

I first stratified the seeds for 3 months in the fridge in air tight containers. Today, primed the seeds. Meaning, I kickstarted their germination. By boiling a large pot of water and letting it cool until I could stand the temp with my hand. Hydrogen peroxide was then added (about 10-15% total volume). Seeds were dropped in, and different sources / species were kept separate if they looked similar.

The important thing is that the seeds soak 24 hours and the water is re-heated if you don't see tiny bubbles around the seed or a white foam. The hydrogen peroxide helps the seed coat imbibe oxygen. This technique can help overcome dormancy and scarification issues that may involve sulfuric or hydrocloric acid. Nothing is less fun than than filing seed edges or mixing acids.


The smaller pot with the white pine seeds cooled too fast, so no bubbles yet. Will reheat as necessary, but it's better to use a larger pot.

 

[0soyoung]

This is the 3% hydrogen peroxide one finds a the pharmacy/grocery store?

 

[milehigh_7]

I do the same with Texas Ebony. The other thing it does is kill any fungus and other beasties that might be living on the seed.

 

[just.wing.it]

Makes me wish I'd done that with my sakura seeds.....oh well.
Good stuff to learn though, thanks!

 

[sorce]

and the water is re-heated if you don't see tiny bubbles around the seed or a white foam.

Reheated with the seeds?

Or do you remove the fizzy ones?

Or remove them all reheat and put the non fizzy ones back at hand temp?

Sorce

 

[Owen Reich]

This is the 3% hydrogen peroxide one finds a the pharmacy/grocery store?

That's correct. I useds to buy the higher concentration bottle, but now I just add more.

 

[Owen Reich]

Reheated with the seeds?

Or do you remove the fizzy ones?

Or remove them all reheat and put the non fizzy ones back at hand temp?

Sorce

Seeds stay in and I just monitor the heat.

If I had a lab, or that much free time, I'd set something up to keep the temp uniform for 24 hours.

 

[bwaynef]

After I soak the seeds in hot water (in a Yeti 32oz tumbler so it stays hotter longer), I let 'em soak in straight (3%) peroxide until I remember to take 'em out. That can be an hour or another day. I got about 150% germination on Zelkovas. I'll let you know how I fared with JMaple soon, and hopefully with JWP and Tilia cordata/Little-leaf Lime a bit later.

 

[Owen Reich]

After I soak the seeds in hot water (in a Yeti 32oz tumbler so it stays hotter longer), I let 'em soak in straight (3%) peroxide until I remember to take 'em out. That can be an hour or another day. I got about 150% germination on Zelkovas. I'll let you know how I fared with JMaple soon, and hopefully with JWP and Tilia cordata/Little-leaf Lime a bit later.

Good idea on the tumbler!

 

[aml1014]

150% germination

I'm confused, did the seeds reproduce underground?

Aaron

 

[milehigh_7]

This is the 3% hydrogen peroxide one finds a the pharmacy/grocery store?

Yep I use 1:5 peroxide/ water ratio I'd be interested to hear what @Owen Reich uses for a dilution.

 

[0soyoung]

Yep I use 1:5 peroxide/ water ratio I'd be interested to hear what @Owen Reich uses for a dilution.

Well, he said:

By boiling a large pot of water and letting it cool until I could stand the temp with my hand. Hydrogen peroxide was then added (about 10-15% total volume).

I am assuming that when he says peroxide is 10%-15% of the volume he means something like 1 cup of store bought peroxide right out of the bottle in 9 cups of water. I presume you describe things similarly.

A chemist would say (or I imagine, since it has been a number of years since I talked with one ) that a 0.3% peroxide solution is made by putting one cup of 3% peroxide in 9 cups of water. Your 1 cup of 3% peroxide in 5 cups of water makes a solution that is (3%/6 =) 0.5% peroxide, not quite twice as strong. Both solutions are quite a bit stronger than I use as an antifungal/antibacterial (2 tbs/qt = 2/64 = 1/32; 3%/32 0.09375% --> close enough for me to call it 0.1% or 1000 ppm), so there shouldn't be anything fungal or bacterial living either of your's seed coats.

 

[bwaynef]

I'm confused, did the seeds reproduce underground?

Aaron

I may be given to a bit of hyperbole from time to time. Stated another way, more sprouted than I expected.

 

[Paulpash]

This is the time of year I sow seeds in Nashville. Generally speaking, the book Dirr's Manual of Woody Lanscape Plant Propagation is a relaible resource for seed prep; stratification and scarification to be exact. Asexual propagation techniques are excellent.

This post is about a little trick to increase germination rates (for the seeds that are viable). The seeds in photos are Pinus bungeana from Schumacher Seed and Pinus parviflora from a questionable Chinese source. Some of the seed packets were not even pine . A few thick seedcoat tropicals as well.

I first stratified the seeds for 3 months in the fridge in air tight containers. Today, primed the seeds. Meaning, I kickstarted their germination. By boiling a large pot of water and letting it cool until I could stand the temp with my hand. Hydrogen peroxide was then added (about 10-15% total volume). Seeds were dropped in, and different sources / species were kept separate if they looked similar.

The important thing is that the seeds soak 24 hours and the water is re-heated if you don't see tiny bubbles around the seed or a white foam. The hydrogen peroxide helps the seed coat imbibe oxygen. This technique can help overcome dormancy and scarification issues that may involve sulfuric or hydrocloric acid. Nothing is less fun than than filing seed edges or mixing acids.


The smaller pot with the white pine seeds cooled too fast, so no bubbles yet. Will reheat as necessary, but it's better to use a larger pot.

I hope you & Bjorn are gonna hook up now he's announced he's coming back to the States [Nashville]. You two were a great team on Bonsai Art of Japan, probably the most informative series on bonsai ever on YouTube. Thanks for the seed germination tips

 

[R3x]

Interesting. I see the point with hydrogen peroxide. But I'm buffled about the soaking in warm water AFTER cold stratification. Even more about the re-heating. What one can usually read is putting seeds into warm water for 24hrs BEFORE putting them into cold. Also you keep them in wet sand or something like that while in cold. When in fridge do you keep them moist or wet?

The usual explanation for stratification is mimicking natural processes. When the seed is ripe in autumn it falls to wet ground where water starts soaking to it (that is the part where you put it into warm water). It stays in the wet ground through winter (that is the part where you put it into fridge). In the spring when it starts getting warmer it will sprout (that is the part where you just plant them and wait). Your process however seems totally different to this (at least to me). Care to explain the idea behind it?

 

[Owen Reich]

My seeds do no stay wet over winter. You can use moist sand, but I stopped doing that years ago as it didn't affect my germination rate for trees and shrubs.

The warm water could be simulating a rise in soil temp; which would be like Spring.

The re-heating just keeps the water warmer longer, as I do not keep the heat regulated for 24 hours.

This is what I do. There are many ways. If your way works, add the H2O2 as a trial and evaluate.

Warm water soaking before cold stratification could be used I suppose for breaking a double dormancy that some seed have. For some real fun, find a species that needs smoke to germinate.

 

[sorce]

For some real fun, find a species that needs smoke to germinate.

Those all germinate automatically around me!

I did my Burning Bush and Hawthorne seeds like this....

I didn't get any bubbles, and I upped the temp and dosage of HP a second time...

In a tumbler!

They plumped, and are still green inside, so I planted another tray 6\6 inside, and sowed the rest outside.

Looking good.

Thanks!

Sorce

 

[atlarsenal]

After I soak the seeds in hot water (in a Yeti 32oz tumbler so it stays hotter longer), I let 'em soak in straight (3%) peroxide until I remember to take 'em out. That can be an hour or another day. I got about 150% germination on Zelkovas. I'll let you know how I fared with JMaple soon, and hopefully with JWP and Tilia cordata/Little-leaf Lime a bit later.

@bwaynef do you do this before or after stratification?

 

[bwaynef]

This is the scarification process that happens before stratification. Some folks knick the seed coat. Some soak in sulfuric acid. Some seeds are ok just soaking in hot water.

 

[atlarsenal]

Thanks, that’s what I was thinking but I wanted to clarify because @Owen Reich was stating he did the soak after after stratification.