ah, terrarium growing! this is really one of the most useful methods of growing/propagating, bar-none, in my book.

i have an exceptionally warm office at work that stays about 80 degrees all the time in the winter. the thought occured to me that i should make use of the free heat (and free electricity) so i set up a 10 gallon aquarium as my first terrarium.

i used a mix of perlite, potting soil, sphagnum peat moss and a bit of vermiculite (can't remember what the proportion was exactly, i just mixed until it felt right). i keep an overhead aquarium light over it on at all times and since i don't have a lid, i used saran wrap over the top. this has been my best terrarium. i lay a leaf down and it roots and grows 90% of the time. i have some harder/more treasured species in there (B. amphioxus, bipinnatifida, nimbaensis, u192 etc.) as well as some miniatures and a bunch of leaves/plantlets in different stages. i have a small orchid (platystele) and a dischidia (ruscifolia) in there just kicking around in no soil since it stays pretty humid.
funny thing, the soil depth is less than a couple inches and things LOVE it in there.

i have another terrarium in my home with the same mix and the same condition of the light always being on, but since it's colder at my place, it doesn't do as well. i have some minis in that one as well, and some other established plants. there is another terrarium next to the great one in my office that's smaller (5 gallon) and has the same set up, but for some reason it never took off. it has episcias and a couple potted begonias in it.

another terrarium set up in my office just houses potted plants and recently potted plantlets. this one doesn't do as well since i actually had a lid on this one and lined it with saran (it was a reptile tank with the mesh top). because the lid sat flush, i think it stayed too humid with too little air flow and i had a couple things rot. this one i set up as an emergency terrarium when i moved and my plants hated my new place...turns out some of them hated the terrarium even more! oh well, i guess i learned an important lesson about air flow.

in any case, i haven't used charcoal and i'm wondering if i should start--but the one that's going so well in my office has been such a boon that i'm sorta living by the "don't mess with it" philosophy. the other three definitely have room for improvement, too. i'm thinking of using an old undertank heater for the one at home.

(i think i ramble too much?)
-ming

Not at all, Ming--it seems to me anyway that those ramblings work out and explain how to do it much better than a quicker sketchier explanation. Maybe I'm just making excuses for myself, 'cause I sure ramble, but half an explanation could be very misleading. Some of the aroid people use heating mats under their plants and I've been thinking that might help with some of these tropical types like the african begonias. They do very well for me in the summer but I often lose them in the winter because the house is pretty chilly. Often put things I'm propping on the top shelf of my lightstand for the extra warmth, but it's off at night when they need it most. There's a good article on the ABS website about terrarium growing for anyone interested.
Nancy

you know, i almost lost a few of my african plants last year, too. the ones that almost went were 'Buttercup' and prismatocarpa. i had 'Dollar Down' almost go out, too, and my 'Abu Dhabi' was in sad shape. i think those little minis can be so delicate! do you feel like your terrarium environment stays fairly stable, or do you have fluctuation within those closed environments?

-ming

It seems pretty stable most the time I think, but I'm not sure they mind a little instability as long as it's warm. I'm amazed sometimes at how well they do uncovered outside, even on the rare occasions when we get a cool front in the summer (like every few years). The light stand I use most these days is against an inside wall so it's pretty protected from fluctuations but fairly cool in 'winter'. We really should get new windows with more insulating properties--it would save the price several times over I'm sure especially in cooling bills in the summer--but I'm kinda silly about liking more air exchange than is good for the power bills! Just the light from the fluorescents brings it up over 70 and I think it's warmer under domes or in terrariums (heat is set at 68 'cause dh is cold). It's a LOT warmer outside--we consider it a blessing when the temp drops much below 80 at night. And quite steadily so for months and months. I'd guess maybe six months or so, with nice weather now and in the late fall, and two or three months when it actually gets below freezing a few times. It's a different kind of challenge from when I lived in Oregon, or Nebraska--things that love the summer die in the winter, and things that will take the winter melt in the summer. Interesting. I've always enjoyed a challenge. Fortunately!
Nancy

I would like to make a small terrarium for my desk at work. My desk receives no sunlight, so the terrarium would have to depend on the fluorescent task light under my cabinet (oh the joys of cubicle living).

I've had great luck with a few small terrariums in the past, but they all received filtered sunlight.

Has anyone had luck growing a small rhizomatous begonia in a terrarium that only receives fluorescent lighting? My plan is to have one begonia in a small fish bowl/bubble.

thanks!
trey

This is not very informational, but I wrote a blog post last month about having to divide a gigantic (for the cultivar) Begonia 'Buttercup' which was trapped inside a terrarium - you might be interested. Still haven't replanted the thing, but this thread has inspired me to try and find the time to do so.

Here's the post - http://transitionalgardener.blogspot.com/2009/02/only-for-now.html

Here is a link that might be useful: The Transitional Gardener (blog)

Most begonias do very good under fluorescent lights. 12 hours or more will do the trick.

Trey I have always grown minis in terrariums under fluorescents, sometimes with ambient daylight, sometimes not. They all do fine as long as they aren't too wet, and some even do well in tighly closed, drippy wet terrariums ('Little Night Music' took over everything in those conditions, as I was warned it would...)

I had that one, a very small bowerae looking one, and some Sinningia pusilla hybrid all growing in a closed bubble bowl under a cubicle desk light for about 2 years, they looked fine. I had it sitting up on a small wood box to get it where it was about a foot from the tube, and very rarely added water so it would stay on the dry side. They only got 8 hours per day.

If the leaves get too tall and skinny you might consider a clip on light with a spiral fluorescent tube. Get a daylight tube and it'll be healthier light for you, too.

Most of my terrariums are pretty much as Nancy described hers up there a few years ago.

Thanks very much for the tips! I'll post some pics when I get my terrarium built.

Cheers!
Trey