Hi, I think you're getting way ahead of yourself here, with all good intentions. You probably won't have a lot of luck with those seeds off the bat, and in any case, growing from seed (of any kind) may be a nice sideline to working with already grown trees, but otherwise will frustrate you, as having something old enough to be able to work with takes years. The way trees that look 'old' and interesting get to do that and still be small is by starting with larger ones and cutting them back, not by stunting their growth when they're a few months old. You'd be much better off to start with a nursery one of 3-5 yrs (1 gal. pot) and learn that way. But before rushing out to do that (in zone 5), be aware that this is not the time of year to be starting out - everything's just going dormant now and you'd be better off to wait for spring, and spending the winter learning more about growing bonsai. Look at www.bonsai4me.com, www.evergreengardenworks.com (for more than evergreens), www.bonsaihunk.us/cultural.html (re 'indoor' tropicals), and find a local club to join so you can see how things are actually done and ask all the questions that will come up (endless!). Bonsai pots, BTW, are usually used to display trees that have been trained over long periods of time as they will slow grow to a trickle, but you first want good growth (either right in the ground or a 'training' box if outdoors) to develop fat trunks and more options branch-wise for styling, so you have lots of time to worry about them later on (years).

Thanks, Lucy.
One more question - is a "training pot" just a regular flower pot or what? If so, about what dimensions would it be?
Thanks,
-Jmcat

It can be anything from a not-deep, but wide-ish (relative to the rootball) wood box of spaced slats (screened) that encourages lateral root growth either in the ground (just lift in spring, hack off whatever's outside the slats/screens and put into a bonsai pot (with the possibility of a smaller one the next year) or smaller box, to a lowish/wide-ish large pot. Growing out nontropicals right in the ground is the fastest way to go though, but of course depends on the soil, your access to the ground, and the tree. But there's so much more to it all... and a few tips here won't do the job, honestly, so at least look at those other sites just for starters, then lots of books and a club.

Could you define "not-deep, but wide-ish"? What would the dimensions be in inches?
Thanks again,
-Jmcat

I think you're misunderstanding... training boxes are for large(r) trees that you have either cut down (or dug up.. but that's for another time) but now wish to continue developing as if they were in the ground, but for some reason in-ground planting is not possible. They are not something you'd use on a little seedling or anything you'll need for some time. And it's impossible to say how large it should be - it depends on the tree. The point is that it should be quite sizable in relation to the rootball, as opposed to a bonsai pot that would otherwise fit but not allow fast growth.

JmCat - It's important that you understand about patience in bonsai - lots of it. You are not going to get anywhere if you want an 'instant' tree unless you spend a lot on one already trained by someone else, and then you'll get home with it and not have a clue how to keep it alive. I gave you those links so you can get an idea about basics, but the learning curve is long and slow - those are fairly generalized and you need to have a better overall approach as well as more focused (on one tree at a time) re the horticultural aspects before you jump ahead. Training box trees are usually for e.g. 5-10+' tall, and/or at least 5 yr old trees, and if you have any decent ground to grow things in, that's better than a box.

Last sentence should say "Training boxes are usually... box".

I realize that doing this will not be an overnight process and that it could take at least 5 years. However, I would still like to give it a try. I am also thinking of taking a cutting / digging up an unwanted elm in our yard. I assume that cuttings should be taken in the spring. However, I am wondering what time of year would be good to dig it up (it is in a rock bed, so I don't know whether I'll be able to dig it up or not).
Again, I am aware that this will take a few years. I will keep in mind your suggestion of buying a bonsai tree to take care of, but I am not currently interested in doing that.
Thanks,
-Jmcat

Bad time to dig deciduous trees, very bad - early spring (as soon as you can dig) is best. How large is it and how big around is the trunk near the soil? When you dig it in spring, it'll need to be in light shade for the season, and well watered. Try to get the largest rootball you can. If taking it out of the rocks means leaving it with almost no roots, leave it alone.

I looked at it after I posted, and, as we have kept trying to get rid of it for a while, it has been cut off too many times to be dug up for bonsai (it has many short stubs and small branches at its base rather than a main trunk).
As for the width, I don't know, but I think it is wider than I would want. It might be useful for someone, but personally I don't really like the common "old tree" (unrealistically thick and tapered trunk) look. I think (currently) that the widest I would want the trunk is 2".
Since I'm not digging it up, I assume the cutting(s) would be taken in spring?
Thanks,
-Jmcat

Oh, and one more thing: I was thinking that this elm tree would be an ideal tree to start with, given that we have tried to kill it for so long and have not succeeded yet. Of course, I'll probably manage to find the one branch that will die immediately...
-Jmcat