There is no blanket answer to your question ;-(

It depends on what you are trying to grow, the growing conditions,how fast/large you want it to grow , weather ,daily care , etc.

Bamboo ? Do you know how many different cultivars there are and sizes from grass-like to timber for buildings?

I suggest you just look up each individual plant for potting recommendations.

Well, this is a tough question to answer. I'll give you a little push down the road, but it all depends on what you want to plant. Here is some of what has worked for me.

Alpine plants need sharp drainage, and can tolerate a little drying out better than most. So, you will need a soil that doesn't hold a lot of water.

Have planted Portulaca and some other annuals in planters that are around 6' deep; but Portulaca can tolerate hot sun and some dry condition.

For annuals I generally use ProMix which I get in big bales from my local nursery pals. However, ProMix has a lot of peat moss in it, and depending on the size of your project, there are times when the whole pot will benefit from being immersed in a container of water to saturate the peat moss ball which can develop around the roots. This (obviously :)) helps the hypertufa absorb some water for the plant roots.

I have not had the roots invade the walls of planters, but that doesn't mean it won't happen if you plant something strong-rooted and/or invasive -- I wouldn't put it past bamboo to invade -- depending on which cultivar you plant. Two years ago some Portulaca seeds got down into the spaces in the walls of a planter, over-wintered, and tiny Portulaca plants were coming up from the walls of the planter last summer.

I try to always make my large pots and troughs at least 10" deep, and make sure to put drainage holes in during construction or use a drill to add them later. How deep you make planter is based on what you intend to plant in it. Also, make those walls 2" to 3" thick on big planters for strength.

So, just treat your hypertufa planters pretty much like any other planter you would use and you should be okay.

Depending on the climatic conditions where you live, you could probably estimate how deep your planters should be by how well they do in regular plant pots. Do 12"w x 8" d pots dry out too fast where you live? If they do well at the 8" depth, you could try that depth for your tufa pots.

Liking bamboo as I do, I have not seen anything that advised planting bamboo long-term in pots -- ANY kind of pot. Bamboo is a fairly rampant grower, even the clumping kinds. If you wanted to keep it in pots for a couple of years or so (depending on variety), you might try something on the size of half a wine barrel, and if I used anything, I would use concrete. Tufa just isn't strong enough. And concrete in the size you would need would be pretty heavy, even empty.

Any pot you use for bamboo should also be smaller at the bottom than at the top. This way, when the roots start to run, they would hit the wall and be deflected UP, and start coming out of the soil, so you could cut them off.

There's a lot of informed growers of bamboo over at the GW Bamboo forum. You might ask for some info there.

Sue

Thank you all for your replies. Gardening is such a complex subject, and an intimidating one, to me -- even harder than cooking palatable meals for myself! I'm a new homeowner, and and an absolute novice at gardening. I'm not even asking very well-tuned questions at this point, I'm afraid. Perhaps a better way for me to benefit from your experience would be to leave things much more open-ended, and let you draw from your complete knowledge base, if you were so inclined to help me any further. Here's a more succinct statement of my position on gardening: think "bachelor's paradigm". Semi-domesticated male seeks cheap, attractive, low maintenance and fertile light drinker of a yard. I'm sick to death of this unkempt skank I've been seeing for the past two years. ok - 4 years. I've neglected her horribly. Alright, I can't deny that I DO love her! But I'm just not cut out for a heavy commitment! I need a more robust and independent yard that isn't so needy and fickle. I'm ready to do more than nothing, but I can never replace the sensitive WOMAN who had a relationship with my yard before me. I..I NEED COUNSELLING. The whole neighborhood knows what's going on; I just can't hide my dysfunction any more. I admit that I'm powerless over this problem. Please..I'm reaching out for help.. How did things ever become so hopeless? buh..huh-huh-huh...I need a beer. I NEED one! ..hey, what're you looking at? Don't you judge me! DON'T YOU JUDGE ME!!

..here's a "succinct" reply...my heart bleeds... :-)

Do you reside on Wysteria Lane?

Actually, I am a jester in the court of the HAPLESSburgs.. BADA BING!

I grow bamboo in pots - saw some on a garden tour where the owner had built a long trough out of wood, the bamboo filled it completely and she had it on rollers to position to block the afternoon sun as it moved. Said she'd had it for years and years. You can keep bamboo in pots for quite a few years and it is lovely. Every so many years you may have to knock it out of the pot, divide and replant but you have to do that with many plants. The larger problem for me is that the pots blow over in the wind (I like the tall bamboo). Too shallow of a pot and, in wind, your bamboo may just uproot itself out. To not have the tall bamboo topple out of the pot on it's own - I'd say your planter should be at least as deep as a 5 gallon pot. Again. if not subject to wind - shallower would be fine. To keep tall things in pots when I replant them and they don't yet have enough roots to hang in there themselves - I just lay a brick right up around the trunk all the way around (3 bricks usually). To get them to grow fast, use nitrogen fertilizer (like a grass feeder), to slow them down once your pot is filling out go *really* slow on fertilizer.

You can find pics on the web of bamboo breaking out of pots - I'd guess all of those are 5 years old or much more - the home gardener can simply divide the plant to have this not happen. There are always takers for free bamboo.

I do grow mostly clumpers with the exception of black bamboo which is a runner. I keep a cement paving stone under each pot and just once/year do a thorough check around the bottom of the pots to be sure the bamboo hasn't escaped into the ground (the paver raises it enough to be easy to visually see any roots growing out the bottom).

As mentioned - other plant's depth all depends on the plant - catctus in troughs only need inches, fast growers or things you want to get big may need a 15 gallon pot size. Be SURE to thoroughly rinse/soak your new tufa pots as cement itself is too limey and will kill plants if you don't leach it for a bit before planting.

Good Luck.

bamboo needs ample water to grow. if you don't have a sprinkler system, or at least a fancy timer to water them, or the mindfulness to water by hand frequently enough, and the money to pay for the water bill each month, you might want to stick to a more drought-tolerant plant..
might i suggest starting with an extremely thick mulch of wood chips/other organic materials? you can stick food scraps under the chips to make bad soil into good soil. also, this helps with the whole water deal.
yes, your neighbors will think the mulch is weird, but better to look like a weirdo than a fool, right?
while you're at it, see how much horse manure you can get delivered. compost it in piles, and then stick it, too, under your mulch. and on your bamboo too.