There are three main types of pots, and have different characteristics that you’ll want to keep in mind. All three types come in a range of sizes and variations, but the key idea is that they affect water evaporation from the media differently.
The three kinds are:
1) Plastic
2) Wooden/air slat and net pots
3) Terra cotta (unglazed)
All orchid pots need to have drainage. Many decorative vases do not have any drainage holes, and growing orchids in containers with no drainage is not something I’d recommend (although I’ve seen it done before, usually by some clueless grower, and always leave puzzled as to why it worked for that plant). You can use a decorative vase if you keep the orchid in a plastic pot that fits inside the vase. When you need to water, just take the plant in the plastic pot out.
PLASTIC POTS
Plastic pots are cheap, abundant, and reusable. They also work very well. Just select the right size pot for your plant’s root system (not too big, and not too small), fill it with your plant and moistened media (this tip is for new growers who may not know to do this).
WOODEN AIR SLAT POTS AND PLASTIC NET POTS
These aren’t really pots so much as open-air receptacles for holding orchids. You use this kind of container when you want a lot of air movement around your orchid and extra aeration at the root zone. Many growers prefer to use sphagnum moss in these slat/net pots, but if you use a fine mesh liner, you can use bark as well.
The thing to keep in mind is that the media will dry out much more quickly in these slat/net pots, and that’s kind of the point. Growing in pots like this, especially hung outside under shade, means you’ll get lots of air movement around the plant and the media, and hence plenty of evaporation. This high rate of evaporation means you can water more frequently, and if the plant is growing well, you can get some very robust growth for orchids suited to this style of growing (not all are). Generally epiphytic orchids will do very well grown like this.
UNGLAZED TERRA COTTA POTS
Many skilled orchid growers prefer using unglazed terra cotta pots. They’re cheap and easy to find. Unglazed terra cotta has one tremendous advantage over the other pot types: the micropores in the terra cotta wick away moisture from the media AND reduce the temperature at the root zone. With good air movement around the pot, you’ll have essentially created an evaporative cooler for your orchid!
While many orchids don’t really care too much about what kinds of pots their grown in, one of the best Masdevallia growers I’ve known grew all of his Masdies and Pleurothallids in unglazed terra cotta. He used New Zealand Sphagnum Moss (often with a Styrofoam peanut(s) at the bottom of the pot), and the plants grew to perfection. Of course, his greenhouse conditions also contributed mightily to his success, but a home grower can do well with unglazed terra cotta, too.
If you grow in an area that is generally known to be too hot to grow, say, Masdevallias, growing in terra cotta might just work. I read years ago of some growers in Louisiana who did just this, growing Masdevallias mounted to terra cotta shingles. Certainly worth trying if you live in a hot area but have become obsessed with some cool-growing orchids!
One key concept here: the more evaporative your pot, the more often you can water. The more often you can water (without keeping the roots overly wet), the faster the plant can take up nutrients and grow. If you had a plant growing in media/pot/conditions that you could water in the morning, and would dry out to mild dampness by evening, AND the plant was receiving enough light to photosynthesize at an optimal rate, in theory you could water every day and get some amazing growth. This is an experiment I’ve had in mind for quite some time, and once we set it up and get some long-term results, we’ll definitely post it on our website (orchidinsanity.com).
I suspect that many orchids in the jungle naturally experience this kind of near-optimal growth conditions – aerated roots, high humidity, the right amount of light, and daily rain, picking up plenty of detritus, dead bugs, and bird poop for nutrition.
Anyways, all that being said, plastic pots work just fine. If you’re a new grower, start with regular plastic pots. While it is tempting to try the other types of pots with all this talk of evaporative cooling and optimal growth, the other kinds of pots have too many variables to think about for an inexperienced grower, and when you’re starting out, you want to reduce the number of variables to a bare minimum so that you can develop a baseline of experience for what works for you. I wish I had done this when I first started out, but I was too excited about optimizing conditions when, really, I hardly had any experience. It was a very costly mistake, and a lot of orchid paid with their lives because of my impatience and ineptitude.