2021 Forest from seed division: Sean’s acer palmatum and acer sieboldianum forest prospects

[Sean Walker]

I have seeds from various palmatums in stratification and some now out to grow. And the siebolds are in warm strat and aren‘t going to out to grow for months.
Here are some palmatums I have under the lights. The ones with leaves were planted as they opened up in the fridge starting December 18th which can be verified by the pms with a fellow member when I found some had opened what I thought was early after only being the fridge for 60 some odd days and I hadn’t even set up a grow area yet. And the other pic of 2 flats is of a couple bags I found with several busting out so I sowed them all and covered a bit.

 

[AlainK]

Hi Sean,
On the last photo I can read "Warm stratify for 120 days, cold stratify for 120 days".

On the Sheffield's Seed Company website, I read :

Growing Info, follow in order:
Scarification: Soak in water, let stand in water for 24 hours.
Stratification: cold stratify for 120 days.
Germination: Sow seed 1/4 inch deep, tamp the soil, mulch the seed bed.
Other: fall sowing in mulched beds is prefered to artificial stratification.
What do they mean by "scarification" ? Is that just simply soaking them or actually scarifying them ?

Where are your seeds from ?

I have Acer sieboldianum sent to me from England that have been in warm stratification for about 40 days now, and I got another batch of seeds from someone esle in Europe. I had read Sheffield's recommendations meanwhile, so this second lot is in cold stratification.

 

[Sean Walker]

They are from Sheffield’s
They were a dried batch. And from the couple other acers I’ve looked at on there, the dried seeds needed the warm strat then on to cold? I also have a palmatum that reads it requires the same process. So I assumed because they were older seeds and dried that this was the norm for acers. It’s my first go at growing seeds this year so I’ve been doing a bit of assuming

 

[AlainK]

Thanks.

I also have a palmatum that reads it requires the same process.

This is very surprising. I've grown acer seeds from different origins, and most of the time they take less than 3 months of cold stratification to begin sprouting.
The risk with warm stratification is that they might sprout very early, as you've experienced. It should be OK if you can keep them in a cool, wel-lit greenhouse.
There are many species of Acer and they don't all need the same treatment.

 

[Sean Walker]

I have them sitting on my heating duct in their bags with moistened “orchid”moss. And I check them regularly cuz I don’t want to miss them breaking out early and possibly dying.

 

[AlainK]

Your palmatums look as if they're on the right track, they look healthy. Apart from the heating duct, is there any heating in the room, what's the average temperature there ? If it's too warm they risk to be "elongated" and more prone to sudden death : have you/do oyou apply a mild fungicide treatment ?

OK, that's a lot of questions, I don't want to pester you but I'm a fan of trees grown from seeds, esp. all varieties of maples

 

[Sean Walker]

Well I used the orchid moss because I read its more resistant to mold than a lot of things used so knowing they were in for 120 warm and 120 cold I thought it working be best.I have thermometer there and they stay about 60-70 F and the duct is in my basement and it is the main trunk that runs to my upstairs.
And the question are great cuz these are the convo’s I read from others that helped me to understand what I know now

 

[Sean Walker]

And nope I haven’t used a fungicide as of yet. What would be recommended if and when I need to use one?
My other few varieties are in cold strat in a couple different things from straight peat to peat w/super fine pine bark and also peat w/fine perlite (don’t ask me why I did that, in hind site it was a dumb move because I can’t see as well if it’s roots popping out or just a piece of perlite sticking to it) I also have some in just a paper towel. Like I mentioned this is my first time so I tried a couple things to see what worked.

 

[AlainK]

Back to bonsai.

60-70 F, that's about 15.5-21°C ?...

In my opinion, that's a bit too warm. I think the temperature could be a little lower, say about 10°c ? (+- 50°F)

About the substrate : I tried different ones, and even for Acer palmatum putting them in a bag without any substrate, like was suggested here in a thread I don't have time to find again, and it worked.

Like I mentioned this is my first time so I tried a couple things to see what worked

For the species that have a very high rate of germination, like you can't miss it, when one has 100 seeds, whatever the "method" if they only get 10 to germinate, they must have missed something

We will all appreciate news from your experience, what worked best, what you would do differently, etc.

 

[AlainK]

Fungicide : as I wrote before your seedlings look very healthy.

For maples, the best treatment is copper-based + sulfur, but I wouldn't use it on young seedlings.

For me "mild fungicide" can be a few drops of Hydrogen peroxide in warm water. Or a decoction of cinammon blended with 15% of 75% alcohool. Used as a spray.

 

[Kanorin]

They are from Sheffield’s
They were a dried batch. And from the couple other acers I’ve looked at on there, the dried seeds needed the warm strat then on to cold? I also have a palmatum that reads it requires the same process. So I assumed because they were older seeds and dried that this was the norm for acers. It’s my first go at growing seeds this year so I’ve been doing a bit of assuming

From my experience and from some reading: with older dry acer seeds, if you just go straight to cold stratification, you'll get about 10-50% germinate. But if you soak them, then warm statify, then cold stratify you'll get considerably better (80%+ if it was stored well).

For freshly collected (I guess this means same year) acer palmatum and sieboldianum, you should be able to go straight to cold stratification and get good rates of germination.

 

[Sean Walker]

Progress

 

[AlainK]

Great !!!

Now you'll have to find the right slab/pot. No hurry, no woories : I often read that it is better to grow each tree separatly before assembling them so some look older, are thicker and taller than the others.

Kudos on you : if you think you have too many, a "garden sale" might help to buy the right container...

 

[Sean Walker]

Great !!!

Now you'll have to find the right slab/pot. No hurry, no woories : I often read that it is better to grow each tree separatly before assembling them so some look older, are thicker and taller than the others.

Kudos on you : if you think you have too many, a "garden sale" might help to buy the right container...

I’m always on the look out for the “right” pots
I have my eye on one or two of the trees so far that I would like to use. There’s a double from one seed that’s was hand planted that could be y’ed below that surface and I also have what looks to be a triple that was mass planted so it could have been 3 seeds together.
And I may have too many. I still have some bags in cold strat I had myself believing that I’ll probably only get a couple per bag ........ well ....... so far so good !

 

[Cable]

Following. I bought seeds for nine different species from Sheffields and started the Acer palmatum soak last night. Arakawas go into a soak today. I'm planning to follow their guidelines of warm strat then cold strat. 120 days each type seems excessive, though. If it is right I wouldn't have germination until September!

@Kanorin, how long do you usually do each step?

 

[AlainK]

@Cable : if the seeds are rather "fresh" (collected say in October-November 2020) palmatums (including 'Arakawa' don't need warm stratification. All the palmatum seeds I got, or collected myself, were cold stratified only, whatever the cultivar, and they usually take 2 or 3 months to germinate.

EDIT: I just realised I've said more or less the same as @Kanorin

 

[Kanorin]

Following. I bought seeds for nine different species from Sheffields and started the Acer palmatum soak last night. Arakawas go into a soak today. I'm planning to follow their guidelines of warm strat then cold strat. 120 days each type seems excessive, though. If it is right I wouldn't have germination until September!

@Kanorin, how long do you usually do each step?

I've never done dried acer palmatum before, but I am trying some styrax japonicus and dogwoods - where a similar warm strat + cold strat is recommended. I don't have any data to report, but I *think* the stratifications don't need to be sequential. So what I've been trying is 3 weeks warm, followed by 3 weeks cold, followed by 3 weeks warm, until I start to see germination. That's just what I'm trying though!

Or try out your own stratification technique and report back with what you find! I would bet you can get at least some of the seeds to germinate following a much briefer warm stratification period...say 3-4 weeks.

 

[AlainK]

So what I've been trying is 3 weeks warm, followed by 3 weeks cold, followed by 3 weeks warm, until I start to see germination. That's just what I'm trying though!

That's exacly what I wanted to try with seeds I gathered in a park that are supposed to need double stratification : Acer japonicum, A. j. 'aconitifolium', acer shirasawanum. But I kept them in trays with soil inside the house (about 20°c) for about 45 days because I didn't plug in the spare fridge in my garage, and to be honest, didn't go to the recycling place to get rid of all the things that will of course be useful one day but is cramming the garage

So a couple of days ago, I just put them outside. The tempsd are going to be quite warm for the season for the coming week (7°C at night, 13°C during the day if I can trust the weather forecast), but it will be cooler after (1°C - which means it could be -2, and 7°C). We'll see, nothing to lose since they were free. I think that cold and warmer periods may be the natural process for breaking seeds dormancy...

If in mid-March nothing happens, I'll have to plug in the fridge I guess

 

[Cable]

@Cable : if the seeds are rather "fresh" (collected say in October-November 2020) palmatums (including 'Arakawa' don't need warm stratification. All the palmatum seeds I got, or collected myself, were cold stratified only, whatever the cultivar, and they usually take 2 or 3 months to germinate.

EDIT: I just realised I've said more or less the same as @Kanorin

The dates are on the seed packets. I'll have to check later, I have a doggo on my lap right now. lol

I've never done dried acer palmatum before, but I am trying some styrax japonicus and dogwoods - where a similar warm strat + cold strat is recommended. I don't have any data to report, but I *think* the stratifications don't need to be sequential. So what I've been trying is 3 weeks warm, followed by 3 weeks cold, followed by 3 weeks warm, until I start to see germination. That's just what I'm trying though!

That's a great idea! I think I'll do that!

 

[Cable]

Ok, so, it looks like the palmatum are from 2010 and the arakawa from 2019.