Bonsais are supposedly outside trees, not indoor plants. I dwouldn't think they would do terribly well in a terrarium, but I guess that also depends on what kind of bonsai.

Sam

Of course you can grow a tree in a terrarium in a bonsai'd way. Of course you need to pick something that will look good, and will flourish in the tank. The same rules apply as for any bonsai.

Thank you.
Theresa

Ive heard figs do pretty well...

Figs are Ficus.

Ive got that much...thanks nath..I was just adding my support...

Hi
Have been growing Bonsai ,correction ,have been dwarfing trees for many years but have only tried 3 specie in a terrarium. I've used compacted shagnum rather than soil
so it's not really Bonsai but I do get very dwarf trees and find them MUCh easier to take care of.The 3 in the terrarium are growing hydroponicly with mixed results.
The main problem is not nearly enough light and of course the terrarium is way to small. I'm also trying several specie of understory palms( I know .you can't Bonsai a palm lol) but you can certainly dwarf it .
One specie that I'd highly recommend is Ficus benjamina.
They are incedibly adaptable,and will endure all kinds of abuse.Unless you can find one already dwarfed you'll need to "train' the plant over a long period of time.
Someday when i get my large terrarium going I'd like to try other types,.There are hundreds of tropical species that should adapt to this very well.
I think the secret would be an understory ,lowland tropical specie that tends to stay small with no distinct wet,dry season needs. Probably have to start them from seed and "trin" them myself lol. May not work but would be fun to try!!
Gary

go with a bonsai ficus, as mentioned before they endure abuse well, depending on the spedies can give youre tank the aged look you are wanting

If you start a ficus from seed or buy a small ficus they often form a round bulb at the base, sortoflike a skiny onion siting above the soils surface, this is considered undesireable and unattractive by about 99% of bonsaists, mainly because no large tree that isn't a mutilated eyesore has this particular trunk formation, so intorder to deal with theis and get a good basal flair to your trunk the thing to do is to chop the bottom of that bulb shaped trunk off right about were it stops flairing outward, and treat it just like a cutting from there on, also the roots and crown you leave behind are likely to send up some new buds and this can be turned into a multitrunk bonsai in time or as a source for new trunks via airlayering, ficus, especialy F. benghalensis and other strangler figs lend themselves extremely well to air layering. Anyways you want to grow and train your plant outside of the terrarium, in as large a pot as posible, people see a small bonsai in a pot and often think that eventually that will become a big Bonsai but the truth is that once its in a pot it grows very little. Also, a true bonsai is the Tree and the Pot, thats litterally what the word means, you can however have Bonsai stock in your terrarium, I would recomend calling it as such if you talk to anyone you suspect to be into bonsai, if they know there stuff they will not resent you for desciding to misuse the word and if they do not they will still know what you mean and they may start useing the word on there own.

With regards to soil condition you will need to have a well drained terrarium, a drainage hole in the bottom wouldn't be a bad idea as well as a sufficient amount of grit in the soil, Sphagnum moss grows roots really well, but tops tend to not do so well and after a few years the trees tend to have exausted themselves, leaving them less than attractive and volnurable to death. You also need to repot a bonsai fairly regularly, unless you have an ungodly large terrarium even a small tree (like a dwarf of some sort) will send out a root system biger than the entire soil content, choking out first your other plants that need soil, then itself, every year untill its grown to appropriate size and then every other year from then on is a good rule of thumb. Clip back all fo the long thick roots and try and leave as many thin fibrous roots near the crown as you can.

Now, regarding the Bonsai forum being a nasty bunch, there is a reason for that, Bonsai is a subject were people think that they can do whatever they want and be successful, people think that they can plant there juniper in straight peat and that they can water every day and that they can keep everything indoors in there sunny east facing window and they will live, this is unfortunately not the truth, if people are not firm then a whole lot of newcomers fail, and then they do not come back to the forum as experiences bonsaists to spread information to others, and the forum dies out, the same thing happens with saltwater aquariums (my other passion) if you go to any of the big forums they are mean places, seemingly, Go check out Reef Central in both cases the less gentle (read as "meaner") the forum is the more sucessful they are at keeping followers, the people who cannot handle the truth cannot handle something as meticulus as Bonsai, its not difficult per say, you just cannot skip certain steps.