I guess what I'm really asking is if deeper is better than wider for these plants.

And if a second year sapling needs something bigger than what I suggested in the first post.

2 foot tall, nice growth.

What are tour long term plan for these?

At Lowes I grabbed some maybe 20 inch around and about that deep pots for about $8 each last year. Cost as much for potting mix to fill them up lol. I finally had a place for a 4ft Metasequoia I was keeping in one. It had roots circling the bottom but besides that looked good for maybe another year.

Stay away from black if you can. It heats up weird.

I agree with toronado3800 i wish u luck with your japanese maples as i could never grow them in my air :)

My short term goal is to keep them as healthy as possible until the end of 2016 and give most of them away as gifts if they look good enough by then. I'll keep a few permanently for the ground or for pots--at that point I don't mind using a much bigger pot if not in the ground.

It sounds like you are saying bigger is better deep and wide. 20" x 20" is probably close to 30 gallon. But I'm not convinced a 2 year old tree needs something that big. In pots that big it will be hard to give them away and/or to repot. Also as you said, 30 gallons of potting mix times 12 is more expensive that I want. Also I want to maximize space so 30 gallon pots are going to eat up horizontal room. (I also have other potted plants).

Do you think a 6" wide by 16" deep is going to be stable and healthy for a 2 year old sapling? Now that I think about giving them away, it kind of seems like the best option. And I have mentioned above I have other plants and limited space.

I have a brick structure around plastic pots that blocks most of the sun, so I am not overly concerned about hot dry pots.

You don't need anything anywhere as near as big as 20"x20" or a 30G pot for a two year old tree!! Excessive moist container soil around a small root system can lead to root rots. Better to size according to the root system now and pot up if necessary down the road. 2 y.o. grafted JM's are generally offered by growers in a nursery gallon - about 6 3/8" diameter and around 7" deep. Your 6"x16" is deeper than necessary but should be fine.

And make sure you use a high quality bark-based (not peat-based) potting medium. That is FAR more important to the long term health of your little trees than is a larger pot size.

as to how to deal with them for winter...

it would be nice to know where you are.. so we have some idea about what winter is like ...

and as far as i am concerned... the most important thing in the pot... is not the pot.. nor the plant .. nor anything else.. its the media ... i see i agree with gal ... go figure.. lol ...

ken

btw, there are no "varieties" of Japanese maple seeds :-) Any seed grown Japanese maple is just a generic species JM - straight Acer palmatum - regardless of the parentage or name of the tree the seed was obtained from. NO cultivars names can be assigned to any seed grown JM.

Gardengal, Thanks for the comparison to grafted plants pots and the reminder about bark based compost. It almost sounds like I could leave the plants in the 4"x9" they are in now for another year. That would be nice.

Re: "Varieties" I sort of didn't think about seeds not being 100% true to the parent plant, and I would not call them the original. But having said that it's hard NOT to call these guys 'varieties'. There is an obvious difference between the little guys that resemble the parent pretty well. I have 6 little red ones from a Sherwood Flame that look identical to one another, 6 pinkish-green Japanese maple trees from a Sango Kaku, and 1 from a Seiryu... . So yeah they are not official but hey you can't beat the price----and they are absolutely beautiful!

Maybe I'll give them each a unique name, like Bardamu's Rufescent Sprout, etc then sell them on eBay. There are so many varieties, and I sure can't tell what's what in this crazy world.

Ken, I'm not any more worried about these plants living through this winter than with my other potted plants--which is a substantial concern. But here I didn't bring it up. I just wanted to know an acceptable pot size for a 2 year old JM tree for next spring. I live in Southern Massachusetts in a spot I like to call z6. I really should put that in my nickname. Since the generic acer palmata are in a small pot now, I am burying the pots in ground under a wind shelter, so I think I've got that part covered---or I am in for an unpleasant surprise!

While many seed grown J. maples may resemble the parent tree(s) and especially when very young, just as many will bear no resemblance to the parent or evolve into a quite different appearance as they age. And while I understand the desire to name your little guys, you can't technically call them anything but Acer palmatum seedlings :-) JM connoisseurs get very picky and dogmatically horticultural about that sort of thing.

That is very interesting garden, I would not have guessed that their appearance would change as they age. It's funny it truly escaped me that these varieties are unstable hybrids, or cultivars or whatever they are.

Are these useful to graft onto or is there a special stock for that?

Do you know how long does it take before their appearance settles in? Looking at the sherwood flame ...generic offspring... now a little more closely I do see their leaves' color ranges from very bright to dull dark.. I would not want to give them to my close non-JM connoisseur friends and family if a generic reject was not even a nice looking fake replica.

All named forms of Japanese maples are propagated asexually, either by grafting or, less frequently, from cuttings. That's the only way you can be sure of getting an exact clonal duplicate of the original tree. And JM's can cross pollinate, so if multiple trees in the vicinity, the seeds could be a cross of any of them and display characteristics of any of them. Or not! Usually their appearance has pretty much stabilized by the time they are a couple of years old but not always. Species or seedling grown JM's can be wonderful, attractive trees with a range of leaf shape and color and growth habits. Many of the named forms we enjoy now started as seedlings and if they showed distinctive characteristics, were grown on and then propagated asexually for a couple of generations to determine if those characteristics were stable. Any J. maple enthusiast would be happy to have one, even if an unnamed form :-) And these seedlings make excellent root stock - it is what the named forms are grafted to: species A. palmatum.

Thanks for the update. I bought a pack of 60 seeds from 4 different plants last year for $10 on ebay. I am doing it again this year. I hope to get more than 12 sprouts next spring, and I think I will since I learned a couple of things about the stratification process these seeds seem to prefer. But this conversation might push me to get a named cultivar or two next year. The ones I see in big box stores do not capture my attention, maybe I'll have to look at gardens more closely. Are there scionwood trades for named japanese maple cultivars on gw?

Instead of box stores, try checking out real retail nurseries and garden centers that carry a good selection of Japanese maples. Or check some of the online specialty JM nurseries. With nearly 1000 registered cultivars (and boxes that carry maybe 5 or 10 at most) I'm sure you will find something that appeals.

Yes, you are right of course, but here in the north end of the east coast I think that garden centers that carry Japanese maples is not like what you have on the west coast. In other words they don't exist here. I could be wrong--as they say, the Baader Meinhof effect. So no scionwood trades on gw? Too bad, that would be fun. I am starting to lean in on splicing wood for fruit trees for apple and pear fun and this would sort of fit in. I see some places on the west coast web sites that sell JM scion wood. Buying a plant is a bit too much capitalistic for my needs since everything is for experimentation and I don't want to plant stuff permanently as a showy thing until I play with it.