JM seedlings - Attributes Identification

[GreatLakesBrad]

Turns out I went a little nuts with seedling starts on JM this spring. Sheffield’s seeds for most, with a couple of eBay arakawa (we shall see) and randomly collected seeds. I’m also planning to take some from my Dads new full moon maple.

All of these young trees have at least produced 2 sets of leaves, which I’ve read is when they will start to show their attributes versus the standard acer P leaves for the first set.

My question for any maple nuts out there: what is your process for identifying unique attributes in a seedling?
I have read varying approaches - of course, I will observe the internodes upon leaf drop in the fall, but I’m struggling to pick out unique trees of the batch. I see some variation, minor differences in leaf size, but for my ‘green’ JM, I don’t notice that much of a different in color and variation 1) as leaves are pushing out and 2) once they are mature.
My atropuroeum (purple) seeds is where I see more variation (see pics) especially now that the 2nd set of leaves are out.


Am I being too inpatient? I realize that some attributes (such as corking of the bark) will not be shown for some time. But what else can I keep an eye out for and when?
Lastly, I have these in an Anderson flat, and a custom made 4 inch deep box. I am planning to separate next spring, unless anyone here suggests that is too soon.

many thanks for any thoughts as always!

 

[Shibui]

First you must realize that none of these seedlings is its parent. Each, being a seedling, has a new set of genes so please don't refer to any of these by the parent cultivar name. The 'Atropurpureum' seedlings are just red leaf Japanese maples until you give each its own new cultivar name.

While we talk about JM as a variable species that variability is nor huge. The range of cultivars we do have have been selected over more than 1000 years of growing seedlings. You should not expect much change in a batch of a few hundred. The genetics of standard green leaf are relatively stable over hundreds of thousands of years so differences are much rarer. That's one of the reasons these are used as root stocks. Seedlings from many of the varieties tend to be more variable - a: because these are already an odd, unstable mix of genes, and b: because they are generally planted close to other cultivars in gardens so cross breeding helps add new genes as well as new combinations.
You can probably see most of the changes in leaf structure now that they have true leaves. Basically that's what you are going to get. There can still be some changes as the plants mature more but leaf color and basic shape is pretty well set now.
Changes in growth habit take longer to establish. By the end of summer you should be able to pick some differences in vigor. Some will be tall and others shorter. Internode length will also be visible by then but be careful because the stronger growers will swamp the slower ones and the slower ones sometimes die from lack of light and root competition while they are still in community pots.
I can see some differences in leaf shape in the red leaf tray - looks like you may have a couple of narrow leaf types which could be interesting.
Traits need to be assessed over a number of years to ensure they are stable as the trees grow. Some growth traits will not really become apparent until the trees have been growing for several years. Autumn color obviously cannot be assessed until then and may still change as they mature.
Some features may be a combination of genetic and environmental conditions so some seedlings that appear to be small growers while in the community tray may suddenly grow better when they have mores space.
New cultivars are not recognized or registered until they have proven to be different and better for a number of years. For landscape trees mature size and general hardiness is required and that will take 10-15 years to assess.

You can see that picking winners is not quite as easy as first thought. Developing new varieties of plants takes a number of years of dedicated work. Growers often spend a lifetime pursuing that elusive new cultivar.

Your seedlings are currently at the stage when I usually start pricking them out into individual pots. They will still grow in the trays but competition for light, water and nutrients will limit growth somewhat while they are together.

 

[Tieball]

Yes.…You did get carried away. I’m confident though that all of these will likely grow into nifty sticks soon enough. And then you’ll know more.

 

[GreatLakesBrad]

Thank you @Shibui for that fantastic run-down! Greatly appreciated. Even if I get one or two somewhat deviating from the norm, that would be rewarding and a fun experiment.
You answered all of my questions AND the additional ones I’ve been pondering, such as your note on crowding being an illusion for vigor, and the low chance that I do find any significant deviation.
I also appreciate the reminder on genetics.

I will debate thinning these out and up-potting some with the backing of your own experience in doing so.

I think a bonsai auctions sale or two is in my future as I struggle to ever throw away a perfectly good tree!

Cheers!

 

[GreatLakesBrad]

Cautiously excited about this one. Looks to me like some variation. Variegated, short internodes and very different than neighboring leaves as you can see!

 

[hinmo24t]

they look great.

cannot recommend this resource enough. love this persons videos and info on maples

this person essentially got me to plan to keep them in 4" containers for 3-5 years!
i might take one or two of 24 i have an put them in 6" next year to see how it goes

 

[Forsoothe!]

The easy work of planting is over and now begins the hard part; culling. To insure that interesting ones are allowed to grow properly you need to pick them out and give them enough space with enough resettling time left this year. That means do it now. Then you need to decide what to do with the rest. Space becomes an issue, muy pronto. Maybe scoop out quart sized groups and sell them for peanuts & shipping here. The sooner, the better because you have other things to do in autumn.

 

[GreatLakesBrad]

The easy work of planting is over and now begins the hard part; culling. To insure that interesting ones are allowed to grow properly you need to pick them out and give them enough space with enough resettling time left this year. That means do it now. Then you need to decide what to do with the rest. Space becomes an issue, muy pronto. Maybe scoop out quart sized groups and sell them for peanuts & shipping here. The sooner, the better because you have other things to do in autumn.

I had been treating separation/culling as an “option” for this first year. Had planned to let them go through winter, and separate out in spring. I’ve been looping a circle of wire at the base (loosely, on the soil) for those that I want to keep.
If you scroll up you can see my setup - you feel this is a must to cull/separate now?

 

[Canada Bonsai]

what is your process for identifying unique attributes in a seedling?

I would say that you are about 2-3 years away from being able to make some very preliminary decisions based on leaf size and shape. In terms of bark textures, you may have to wait as much as 10 years or more. It is a far more time consuming project to understand a strain's growth habits and the way that it reacts to our bonsai interventions like pruning, wiring, fertilization, etc. in terms of healing wounds, branch die back, ramification, leaf size, etc.

My teacher has done this twice with Acer palmatum, and chose 'Yves' Select' and 'Yves' Arakawa'. 'Yves' Select' is very unique:

https://www.facebook.com/107339777649941/posts/160625818988003

I am currently doing this with Acer rubrum, with over 500 seedlings underway.

There is a tremendous amount of variation when working with seeds (see attached), and anybody who has done this with Acer palmatum will know that there is just as much variation -- it does come down to how closely one choose observe things though. In fact, Atropurpureum is famous for the wide variety of cultivars that have been selected from its seedlings (Shojo, Nuresagi, Bloodgood, Moonfire, etc.). However, the fact that Atropurpureum is part of the amoenum group is, for me, very good reason to ignore it completely when it comes to bonsai: Japanese maples in the amoenum group tend to have larger leaves and do not behave or react like the palmatums and dwarves that we tend to use such as Arakawa, Beni Chidori, Deshojo, Kashima, Katsura, Kiyo Hime, Koto Hime, Seigen and Shishigashira. It took me a long time to accept this because some of my favorite cultivars, notably Hogyoku, are in the amoenum group.

Keep in mind that when people talk about 'standard Acer palmatum' it can be misleading--every quality pre-bonsai nursery in Japan that I have spoken to propagates maples via cuttings (or air layers), and their 'standard' strain does not refer to seedlings but to cuttings taken from a mature specimen that has proven its worth over time (it becomes something of a 'house strain').

If your goal is to identify a strain for bonsai (it sounds like it is), be prepared because this is going to require A LOT of space, substrate, pots, etc. over the next decade. Moving forward with the Atropurpureum seedlings really sets the odds against you. If this kind of project interests you, I would invest in acquiring seeds from a source with more promising tendencies.

 

[Arlithrien]

If you have the space, I'd recommend waiting 3-4 year to really let the trees express their full character. I'm on my 2nd year, and over the next weeks/months I will begin accumulating seeds for the 3rd season. I sowed Arakawa seeds as well my first season and 2 years later its still too early to tell which ones will express the rough bark. But I will say the germination rate and vigor of Arakawa seeds has been impressive.

If this is something you plan to do year over year, I suggest investing in some mother plants. Figure out what traits you're chasing and seek varieties that have them. For example, lets say you really like the look of a cultivar but its leaves are too large, well acquire that cultivar and a smaller leaf variety and attempt to cross pollinate them.

 

[Arlithrien]

I am currently doing this with Acer rubrum, with over 500 seedlings underway.

There is a tremendous amount of variation when working with seeds (see attached), and anybody who has done this with Acer palmatum will know that there is just as much variation

Thanks for doing this. Acer rubrum is really an untapped market but it's difficult to source the genetics since they are so vastly distributed across the US. Although it may take many lifetimes, the person to develop an acer rubrum that holds its red color will become very wealthy. The person to develop an acer rubrum that is suited for bonsai will be mildly appreciated.

 

[GreatLakesBrad]

I would say that you are about 2-3 years away from being able to make some very preliminary decisions based on leaf size and shape. In terms of bark textures, you may have to wait as much as 10 years or more. It is a far more time consuming project to understand a strain's growth habits and the way that it reacts to our bonsai interventions like pruning, wiring, fertilization, etc. in terms of healing wounds, branch die back, ramification, leaf size, etc.

My teacher has done this twice with Acer palmatum, and chose 'Yves' Select' and 'Yves' Arakawa'. 'Yves' Select' is very unique:

https://www.facebook.com/107339777649941/posts/160625818988003

I am currently doing this with Acer rubrum, with over 500 seedlings underway.

There is a tremendous amount of variation when working with seeds (see attached), and anybody who has done this with Acer palmatum will know that there is just as much variation -- it does come down to how closely one choose observe things though. In fact, Atropurpureum is famous for the wide variety of cultivars that have been selected from its seedlings (Shojo, Nuresagi, Bloodgood, Moonfire, etc.). However, the fact that Atropurpureum is part of the amoenum group is, for me, very good reason to ignore it completely when it comes to bonsai: Japanese maples in the amoenum group tend to have larger leaves and do not behave or react like the palmatums and dwarves that we tend to use such as Arakawa, Beni Chidori, Deshojo, Kashima, Katsura, Kiyo Hime, Koto Hime, Seigen and Shishigashira. It took me a long time to accept this because some of my favorite cultivars, notably Hogyoku, are in the amoenum group.

Keep in mind that when people talk about 'standard Acer palmatum' it can be misleading--every quality pre-bonsai nursery in Japan that I have spoken to propagates maples via cuttings (or air layers), and their 'standard' strain does not refer to seedlings but to cuttings taken from a mature specimen that has proven its worth over time (it becomes something of a 'house strain').

If your goal is to identify a strain for bonsai (it sounds like it is), be prepared because this is going to require A LOT of space, substrate, pots, etc. over the next decade. Moving forward with the Atropurpureum seedlings really sets the odds against you. If this kind of project interests you, I would invest in acquiring seeds from a source with more promising tendencies.

Awesome overview, thank you! I enjoy watching your projects on Instagram (I’m @greatlakesbonsai, better said as Great Lakes prebonsai).

I’ve got about 100 acer rubrum, desperately hoping to find some suitable for bonsai. Watching that project of your very closely as well!

Currently ~150 acer palmatum. Great tip on atropurpureum - have about 50 of these and will keep that in mind.

30 or so are from Sheffield’s arakawa stock, 100 are ‘generic’ small seed green acer from Sheffield’s as well.

we are currently looking for a new house, and my minimal requirement is an acre, so I plan to plant the ones that are “promising” from my very untrained eye into the ground in a grow area. Should they produce desirable characteristics - great, air layering and cuttings to propagate. If not - move to landscape location or dig up and sell as prebonsai.

appreciate the context on how long of a process this is. I also fully understand that my odds of finding something ‘net new’ is extremely unlikely. I sure enjoy the process though!

@Arlithrien - thanks - I have indeed purchased a few cultivars from Evergreen Gardenworks. One is Ibo Nishiki - a cork bark variety, and the other acer P is “Sazanami.”

 

[Canada Bonsai]

@Brad in GR I had no idea it was you GreatLakes!

An acre is a smart move! That's plenty of space to pursue more maple projects than one person should ever take on

 

[Forsoothe!]

I had been treating separation/culling as an “option” for this first year. Had planned to let them go through winter, and separate out in spring. I’ve been looping a circle of wire at the base (loosely, on the soil) for those that I want to keep.
If you scroll up you can see my setup - you feel this is a must to cull/separate now?

"...The first year they creep, the second year they leap..." There is only so much space, and they all want it and will claim all they can. If you think it looks crowed on top now, wait until you're pulling roots apart. Other have pointed out that you can pretty much tell what they will look like by now, and the only other things like vigor and size will be forthcoming. For bonsai you want those that grow smaller and incidentally slower which are exactly the plants that will be at a disadvantage and suffer from over-crowding. Pull out any that look good as soon as you make that judgement and eventually you will have all you want from a given batch. You will need the flats and the space for 2021's crop of seeds pretty soon, anyway.

 

[Sean Walker]

I waited till a few weeks ago to separate my seedlings and my goodness……..there were a lot of roots to separate. I kept the “eh maybe” interesting and the interesting separate and marked the 4”pots with the traits to see if they hold true. The rest I potted up to ”sell for peanuts” next year. I ended up with 250-300 seedlings. In seeing all of yours I’m glad I’m not the only one who over did it the first time.

 

[Leo in N E Illinois]

@Brad in GR - great project. Green seedlings are more or less bred for uniformity. They are used as grafting understock for propagators grafting the desirable named cultivars for the nursery industry. The "small seed" are somewhat more variable as they are more for the dwarf shrub and bonsai markets, though small seed does not necessarily mean small growth habits. It can mean smaller growth habits, but the traits are not "locked together".

Autumn is of course when the seedlings will distinguish themselves. Also the color of spring growth. You could pick the 25 to 100 most interesting seedlings, compost the rest, or sell the rest. My experience hybridizing orchids suggests that if you keep a group of 25 or more, you have a better chance of having one or two that will be significantly different from the others. Orchids do have a high degree of variability, with line bred trees, like "green Japanese maples" the variability will be lower. With the more exotic sports, like the bamboo leaf type Japanese maples, the variability in a population of seed will be higher. Obviously the more seedlings you keep, the more variation you will be able to observe.

Make yourself a scorecard, a written list, and score your seedlings after Autumn Color has developed. Literal, or virtual. Score your seedlings at least twice a year. Keep the ones that score in the top 25%, dump the rest. Repeat this process Spring and Autumn until you have pared your group of maples down to a number that you can manage, 25 or so is a round number for a backyard, but the more room you have the more you can keep. The more favorable "bonsai traits" a seedling has, the better. My list of bonsai traits is not exhaustive, just my "off the top of my head". You should create your own list of what you deem important. Sort the list to weight the traits most important to you.

Spring new growth color
autumn leaf color
average leaf size
leaf form - for example; lace leaf, bamboo leaf, star shaped with little or no serration, and many more variants.
Internode length - which translates into miniature, dwarf, compact or standard size plants.
branching pattern - some will have a proliferation of branching, some low branches will dominate, some will tend toward being tall whips.
Root habits - there will be some variation
Cuttings - the ability to propagate from cuttings, some cultivars will not root from cuttings. Some cultivars are easy to root from cuttings.
Bark Color and Texture - the bark color of one to 3 year old branches can be anything: green, yellow, pink or red, purple. The texture of bark that forms is normally smooth gray bark, but can be pebbled, plated, corky or ? there is a range, with relatively smooth bark being the normal state. Scoring bark traits may take 10 or more years.

And some selection will happen because of your unique environmental conditions. I suggest not providing much winter protection. This will automatically select for the more cold hardy traits.

Almost all traits you can think of have heritable components. Selection of seedlings best suited for your conditions is a worthy project.

 

[LanceMac10]

"...The first year they creep, the second year they leap..." There is only so much space, and they all want it and will claim all they can. If you think it looks crowed on top now, wait until you're pulling roots apart. Other have pointed out that you can pretty much tell what they will look like by now, and the only other things like vigor and size will be forthcoming. For bonsai you want those that grow smaller and incidentally slower which are exactly the plants that will be at a disadvantage and suffer from over-crowding. Pull out any that look good as soon as you make that judgement and eventually you will have all you want from a given batch. You will need the flats and the space for 2021's crop of seeds pretty soon, anyway.

....it's "sleep, creep, leap"......third year for a ground planting is when you will notice an increase in caliper....

 

[GreatLakesBrad]

@Brad in GR - great project. Green seedlings are more or less bred for uniformity. They are used as grafting understock for propagators grafting the desirable named cultivars for the nursery industry. The "small seed" are somewhat more variable as they are more for the dwarf shrub and bonsai markets, though small seed does not necessarily mean small growth habits. It can mean smaller growth habits, but the traits are not "locked together".

Autumn is of course when the seedlings will distinguish themselves. Also the color of spring growth. You could pick the 25 to 100 most interesting seedlings, compost the rest, or sell the rest. My experience hybridizing orchids suggests that if you keep a group of 25 or more, you have a better chance of having one or two that will be significantly different from the others. Orchids do have a high degree of variability, with line bred trees, like "green Japanese maples" the variability will be lower. With the more exotic sports, like the bamboo leaf type Japanese maples, the variability in a population of seed will be higher. Obviously the more seedlings you keep, the more variation you will be able to observe.

Make yourself a scorecard, a written list, and score your seedlings after Autumn Color has developed. Literal, or virtual. Score your seedlings at least twice a year. Keep the ones that score in the top 25%, dump the rest. Repeat this process Spring and Autumn until you have pared your group of maples down to a number that you can manage, 25 or so is a round number for a backyard, but the more room you have the more you can keep. The more favorable "bonsai traits" a seedling has, the better. My list of bonsai traits is not exhaustive, just my "off the top of my head". You should create your own list of what you deem important. Sort the list to weight the traits most important to you.

Spring new growth color
autumn leaf color
average leaf size
leaf form - for example; lace leaf, bamboo leaf, star shaped with little or no serration, and many more variants.
Internode length - which translates into miniature, dwarf, compact or standard size plants.
branching pattern - some will have a proliferation of branching, some low branches will dominate, some will tend toward being tall whips.
Root habits - there will be some variation
Cuttings - the ability to propagate from cuttings, some cultivars will not root from cuttings. Some cultivars are easy to root from cuttings.
Bark Color and Texture - the bark color of one to 3 year old branches can be anything: green, yellow, pink or red, purple. The texture of bark that forms is normally smooth gray bark, but can be pebbled, plated, corky or ? there is a range, with relatively smooth bark being the normal state. Scoring bark traits may take 10 or more years.

And some selection will happen because of your unique environmental conditions. I suggest not providing much winter protection. This will automatically select for the more cold hardy traits.

Almost all traits you can think of have heritable components. Selection of seedlings best suited for your conditions is a worthy project.

Thanks as always Leo for the brainstorm!

my plan is in line with yours- 25 or so taken from the 100 (I’ll make some forests for fun and use some for bonsai club swaps or auctions). I was pondering the winter hardiness approach and landed in the same spot - mulched around the container, on the ground, over winter, like all of my other trees - and whoever makes it is suitable! Over the first 5 years, I’ve left JM to these conditions and have yet to lose one. I think the 5b to 6a zone is just enough for them, but then again, we haven’t had that cold of winters during that half decade. We shall see.

 

[Leo in N E Illinois]

I have to say, I've enjoyed our relatively mild winters. 2 years ago, we dipped to -17 F here on my side of the Lake. But it only lasted a few hours. I remember the "bad old early 1980's when we would get a 5 day stretch where the daytime highs were 0 F (which is -18 C for the metrically inclined). We had lows around -25 F ( -32 C.) That was cold. A deep breath was life threatening, nose hairs would freeze up, frost in the beard and mustache. Just getting the car started as "cheating death again".