Sorry to say I had no luck with A. griseum seed collected from local trees (four growing in close proximity). Before stratifying, I cut open a sample and roughly 50% contained embryos. As I recall, I warm/moist stratified the seed for three months, then cold/moist for four or five months. Before planting, I squeezed about half of them with a pliers with just enough pressure to pop open the seam of the seed wall. Not a single seed germinated. I even re-stratified the seed for another winter and replanted, with no better results.

I had the same lack of success with A. triflorum seeds (which I purchased).

Well that's a little disheartening! I'm sorry you didn't have any success. I guess I'll have to keep my fingers crossed. Anyone else out there try and actually succeed with this species?

In some 30 years, I have had one seedling of Acer griseum.
this year the squirrels really did a job on the seeds.

If the four together were a grafted clone then there being more than one specimen present would do nothing toward achieving cross-pollination. I think there is something to cross-pollination playing a role with this species as those occasions when I became aware more than a few seedlings were coming up on their own there was more than one seed-raised fruiting tree present.

Of course, even when dozens of them pop up at the same time large quantities of fruits may have been produced, fallen to the ground and come to nothing, the number of seedlings appearing still a small fraction of the number of fruits produced. The general limitations on the reproductive capacity of this species would still be in effect, just helped a bit by cross-pollination.

treeguy,
You have only 10% sound seed, find a tree that yields no less than 30%. Test them by opening up a few before collecting with your Felcos.
I doubt if he is still in business but Howard Ecker from Webster NY, used to grow and sell seedlings. He collected tremendous quantities of seed.
Here is what worked for me for A. griseum, triflora and nikoense: Collect seed in early September, sow in ground seedbed ASAP while the soil is still warm. Sow the seed doubly or triply thick to account for hollow seed.
Seed sown in Fall of '07 will have some germination in Spring '08 but most of it will be in Spring '09. During this whole time you have to keep the sedbed clean, free from weeds, etc. Thats why seedlings are expensive.
FYI, Heritage Seedlings in Salem OR is selling one year seedlings for $3.80, so it can be done.
Sam
PS. beware, you will get some mongrel seedlings, some you can't even identify. You will have to rogue them out since they are worthless. I got a whole batch of griseum x nikoense seedlings one year, very fast growing but couldn't give them away.

Here's what Dirr and Heuser have to say:

"The senior author has cold stratified seed for 90 days, split the fruit wall, extracted the embryos, planted them in vermiculite and most grew. This method is not feasible for large scale propation, but if a few trees are desired and one does not want to wait 2 to 3 years, it might be worth the effort."

About grafting they basically conclude that Grafting to Acer saccharum (Sugar Maple) leaves: "a conspicuous bulge at (the) union. (Acer saccharum is twice the diameter of Acer griseum)." 'The other trifoliate Maples according to most growers are not suitable and naturally, Acer griseum as a rootstock is best.' So as Ron says in so many words, if the trees all look the same they could be of grafted origin.

Overall the discussion leans best to extract the embryo and grow them in vermiculite. Airflow (fans) will keep your seedlings from dampening off problems I'll add to the discussion.

And furthermore it is discussed that the seedlings are kept under 50% shade cloth for the first three years before they are ready to be lined out (or planted to a landscape). It is also discussed that the 'new seedlings' are kept potted (commercially at 28 degrees F in a controlled environment) and no reference is given that the seedlings are ever kept "in the field" but I will assume that is not correct... your call though. Nursery growers will purchase "liners" to grow on for profit for those of you that may not understand that term... 'Hertage Seedlings' by the way is the best seedling (and grafts) nursery I have ever dealt with. Their quality is superior. Thought I'd mention this as well.

Good luck on those Griseum. They are a lucrative moneymaker indeed. And you gotta always grow what you love. I indeed plan to grow these for commercial crop.

Dax

Dirr, Michael A and Heuser, Charles, Jr. ÂThe Reference Manual of Woody Plant Propagation: From Seed to Tissue CultureÂ; (Second Edition 2006); Varsity Press, Inc. ISBN: 0942375092 or ISBN: 13: 978-0-942375-09-1

Thanks all for the info, much appreciated. I'll split my seed batch up and try a couple methods to see which works best.

Here is my current project: when collecting seed, cut in half with pruners and see what percentage are sound like these. Take into account how many good seed you have when you sow the seed.

These below are 50% sound, I de-wing the seed to make it easier to handle.
sow the seed heavy, you can always thin them out later. Overwinter them where they will get both cold and moisture and protect from vermin.
here seedlings germinate when they please, some the year after sowing, some two years after sowing.
Heritage Seedlings is a premier, wholesale grower of tree seedlings in Salem Oregon. Acer griseum is one of their signature species. They are the nation's dominant supplier of this species.

In my case I will likely produce mongrel seedlings but I don't care. My plan is to use them as understock for an exceptional trifoliate maple that I stumbled across last month.

Sam, thanks for the update and info. Keeping them free from vermin is my biggest problem. I never did get any griseum seed to germinate. I collected a few handfuls of maximowiczianum and mandschuricum seed this fall, so here goes on attempt number two at the hard seed coated trifoliate maples!

Will you share what your exceptional trifoliate maple is?

Yes, pic #3 of this thead zoo trees

Very nice! The bark reminds me of triflorum. Does it match a particular species?

That Triflorum is stunning. Are you going to name it?

Anyone have any updates on this?

I've been running several experiments in my apartments. I have 5 sources of A. griseum seed around here. I've done some in 1:1 Sand:Perlite, warm strat. Other fresh seed I've put straight to the fridge in 1:1 Sand:Perlite.

Just today I cracked open and sowed just the embryo into pure sand. I did 8 cells with two per cell.

I'll post the results as they come but wondered if anyone else was still doing griseum by seed?

I got some triflorum to sprout, but the damn things all died the second season.

I've pulled these out of the fridge. So far, 18 days on a heating mat at 72 degrees and still nothing..

If you wanna meet Joyce click HERE She is involved with my State's Master Gardeners. In the video she talks about Paperbark Maple. Do you just want a couple of seedlings, if so scoll ahead to 1:40 and listen to Joyce.

Just about all of us know where there are groupings of A. griseum that were planted several years ago, ie campuses, parks, churches, libraries, etc. If the areas under or nearby these trees are mulched you are in luck. Search these areas for volunteer seedlings. Ask permission before you rescue them. Be forewarned, some of these seedlings will be mongrels pollinated by a different species and useful onlly for future understock. If you are diligent you can find several seedlings this way.

Sam, do you pre soak the seeds and/or scarify before sowing?

Another find today, 11-28-20 along a Maryland highway. Notice the contrast in this planting of about a dozen trees. One shows exceptional fall color. The rest in the background are bare. A. griseum is quite variable. If the red tree is exceptional year after year it may be worthy of clonal propagation.

That one is phenomenal for color! My one paperbark maple is what I would call intermediate for good fall color - on good years it looks like the tree you posted, others it is a mix of red/orange/yellow not unlike a sugar maple. Beautiful nonetheless.

I never did get paperbark seedlings from the trees I originally posted about 3yrs ago. Since then I tried germinating other trifoliate maples. I built a cage out of hardware cloth and 2x4 lumber to keep the vermin out. This worked very well, and I had success with letting mother nature do the work. All trifoliate seedlings germinated the second spring after planting. I now have about a dozen each of A. maximowiczianum, triflorum, and mandschuricum!

A nice thing about the tree in Sam's shopping center picture is they were properly pruned and grown for long term durability in our climate.

(What area in suburban Baltimore is that tidy looking yet needs cart locks? LOL. I've lived in MD for over 15 years now and certain various suburbs of Baltimore are still profoundly mysterious to me. It's too bad whoever planted these didn't work on Quarry Lake at Greenspring. It would be a magnificent setting for some high quality plantings but from what I remember it was very blah. Haven't been there in years)

All the stars lined up this year for this tree. It is one of three planted in front of a library. Notice the abundant seed production. This doesn't happen every year.

I opened several seed with pruners and found no hollow ones, that is quite rare. I have sown the seed, will report back if/when it germinates.

I've sown all the seed I collected this year, about 2 pounds worth.

Hello ”acer Griseum” friends.

I have had my hands on a a pile of Acer Griseum samara’s and tried my luck on them.

As patience is not really my middlename I opened the samara’s and found a lot of viable seeds in them. I managed to germinate a big number of them and they now grow in a propagator until i can move them to my little greenhouse. Here are some pics.

Bravo Contusio Cerebri, a great success story backed up by pix. You must have found a good seed tree(s). 13 year old thread, many post and talk about A. griseum but you showed how its done.

Thank you!

Wow! Amazing. I found a germinating seed under a lovey Acer Griseum today in the Lake District, England. Really excited to see if it comes to anything. Really interesting thread this. 👍🏼

I also have a single Acer Triflorum seeding germinated this spring, so fingers crossed for that!

Wow great!i hope they will flourish!

Another Acer Triflorum seed found today under the tree. I think the cold winter we have had has had a great impact on the seeds.

How nice!

I just came across a group of three Acer Griseum in a shopping centre planting. There were seeds germinating all over the floor. have potted up around 50. They had really varied bark. Beautiful things. This cold winter here has been a huge help!

Still going very nice!