All right now. Here's Part II of the Phalaenopsis profile, where I tell you how to grow them indoors. If you're in the mood for genetics (or interested in finding out about the origins of the song "Yes, We Have No Bananas"), you may want to read Part I first.
There are 60 or so natural Phalaenopsis species, which are distributed throughout Southeast Asia, with a number of species in India, Indonesia, China, Taiwan, the Philippines, Malaysia, and Vietnam (among other places). These all hybridize with one another pretty easily, and with the occasional other orchid genus, which is how we've gotten so many different cultivars. The name Phalaenopsis means "looks like a Phalaena:" Phalaena is the now-obsolete name for a genus of large moths. (I don't know what "Phalaena" means.) This used to make more sense than it does now, as most of the Phalaenopsis species and hybrids available originally were large, more or less "flat," and either white or mostly white, all fairly mothy characteristics. You can still find whites if you want them, but most of the phals I see being sold now are pink or pink-purple.
Phalaenopsis are also surprisingly big business. I mean, orchids in general are gaining in popularity, but phals seem to be the bulk of those: I found one claim that 75% of orchids sold in the U.S. were phals in 2000, and although I'd guess that percentage has maybe dropped slightly in the ten years since, I'm sure it's still pretty close to that. I've been noticing them a lot in the home-makeover shows in the last couple years.1 The range of colors and sizes has expanded as well, mostly through the kinds of breeding I talked about in Part I. If you try hard enough, you can now find phals in white, pink, pink-purple, yellow, dark purple, and then various combinations of those colors in spots, stripes, and gradual shadings. I've also started seeing dwarf varieties in stores recently, which are in the same colors as the others, but at about one-third scale.
I personally only have one Phalaenopsis, and it wasn't my idea: the husband wanted to buy one, and, like with our Murraya paniculata, I tried to talk him out of it, but he did it anyway. It's still alive, after a year, but it hasn't rebloomed, and, frankly, it's not much to look at without blooms, so I wouldn't be heartbroken if it were to die on me or have some kind of horrible garbage-disposal accident2 or something. But that's not a very nice thing to do to a helpless, innocent plant, so part of the motivation for writing this profile was the hope that I could figure out what it wants and get it to reflower, so I could keep my murderous impulses stifled.
Did I succeed? Not exactly. Here's what I got.
LIGHT: General internet consensus is that a bright window without a lot of direct sun is best. A number of sites specifically recommend eastern exposure, but I don't think that's as important as just getting a very bright location without full, all-day-long sun. Some filtered sun (through other plants or sheer curtains) is fine. Plants which get too much sun will scorch; plants which aren't getting enough will just fail to bloom, grow slowly, or be generally weak and dumb-looking. Ideally, you want enough light to tint the undersides of the leaves slightly purple, like so:
Sometimes the top of the leaf will turn slightly red or purple, or leaves will develop a thin red or purple margin. The Internet is divided about whether this is necessarily bad: some sites advise that if you're seeing a differently-colored margin on the leaves, this means the plant is getting too much light, and you need to move it away from the light source a little; other sites say this is the level of light you should be aiming for. Everybody does seem to agree that if you're seeing purple, then you're at about the upper limit of what's acceptable illumination.
Artificial light is also done fairly often; most sites that mention it suggest four 48-inch (1.2 m) fluorescent lights, at a distance of 6-12 inches (15-30 cm) above the plant. This seems really intense to me, by comparison with the recommendations for natural light, but there was a pretty broad consensus.
WATERING: This is probably where I've screwed up the most with mine. Phals don't have large, swollen stems for storing water3 like many other orchids, so they don't handle drought as well. If your plant gets dry to the point of wilting before you water it again, you've waited too long, and this will put stress on the plant. The various websites I found were maddeningly non-specific about how to determine whether a plant is too wet to water, though, and too much water will lead to root rot. The overall impression I get is that it's best to water thoroughly, discard the excess water that drains off, and then let the plant get almost dry, but not entirely dry, before watering again.
I suspect it's probably easier to water plants that are grown in sphagnum moss, as opposed to plants grown in bark;4 in my experience, sphagnum stays more or less the same moisture level through the whole clump, whereas with bark, the top layer can dry out whether the middle of the rootball is wet or dry. (Though see what I have to say at GROOMING.)
Everyone is also very insistent that phals should only be watered in the morning, because the water has to be evaporated off the leaves before night, because standing water on the leaves and cooler temperatures, combined, will lead to leaf rot. One also should be very careful not to let water stand in the growing tip of the plant, because this will also cause rot. I'm sure everybody has good reasons for saying these things, but in the average home environment, where temperatures don't fluctuate that much and the humidity level is likely to be low to begin with, I'm not sure this is really something to get panicky about. Certainly I've watered my plant at night (or maybe more like late afternoon), and I haven't had any crown or leaf rot. But then, I'm a rebel, and I'll never ever be any good.
TEMPERATURE: Phalaenopsis prefer fairly warm temperatures. The usual recommendation is for 75-85F (24-29C) during the day, falling to 65-75F (18-24C) at night. They can go cooler than that if they have to, but try not to make them if you can help it.5 Hotter temperatures, above about 90F/32C, will slow growth, and extreme swings in temperature can cause developing buds to abort. Hot temperatures will also prevent the formation of bloom spikes.
Most of the plants sold in large quantity by retail are able to take fairly big swings in temperature, and you can induce bloom formation by giving the plant temperature swings of 15-20 degrees F (8-11 degrees C) between day and night. Everybody agrees that one night of this is not enough to do it, but precisely how long you have to do it varies from source to source. The optimists say two weeks of this treatment will suffice, and the pessimists say six to eight. The duration and precise temperatures vary according to the ancestry of the plant, which you're unlikely to be able to find without doing a lot of research -- and even if you did find out which species make up your particular hybrid and in what proportions, that still doesn't tell you very directly how much cold your plant can stand. So play it safe, and don't go higher than 85F / 29C in the day or lower than 60F/16C at night.
Plants also need to be kept at least a few inches away from cold windows during the winter: the air near a cold window is much colder than in the rest of the room, even with good air circulation. Phalaenopsis should also be kept away from direct blasts of hot or cold air, as from an air conditioner or heat vent. But these things are true of almost all plants grown indoors.
HUMIDITY: Phalaenopsis will do best in 50-75% relative humidity, which is fairly high for the average house, especially in colder climates, winter, or both.6 They also need good air circulation at the same time, so very local methods of increasing humidity, like misting and pebble trays, aren't that useful. (Some sites recommend misting and pebble trays anyway. I don't really see the point, but if it makes you feel better, I guess.) My personal experience suggests that humidity is not as critical as all that, but then, my personal experience is also that they don't rebloom. So.
PESTS: Phals can come down with more or less everything: scale, thrips, spider mites, fungus, viruses, kindergarteners, whatever. I personally have only ever seen mealybugs. Phalaenopsis aren't especially likely to have pest problems, in my personal experience, but when I asked for suggestions for mite-prone plants, a while back, people suggested Phalaenopsis, among other orchids. So it can happen.
Pesticides that are safe for other plants are not necessarily safe for orchids, so check the labels first to make sure the pesticide in question is labeled for orchids. Wiping plants down with oil and/or dishwashing soap is said to work as well as pesticides on spider mites, possibly better.
We generally didn't try to cure plants that had mealybugs, where I worked: usually we just threw them away, rather than risk spreading the problem to any more plants.
With kindergarteners, removal by hand is usually the best approach, though you'll probably have to repeat treatments regularly. Pesticides are effective, but frowned upon by . . . pretty much everybody.
PROPAGATION: Virtually all large-scale production of Phalaenopsis is done through tissue culture, which is great and interesting and everything but isn't really practical for the home grower.
Growing from seed is a little better, though orchid seeds are incredibly tiny, highly prone to fungal diseases, and a pretty long-term prospect besides, since it may take five to seven years before a seedling is old enough to flower, and by that point, honestly, what are the odds that you're still even going to care what the flower looks like? Plus, even supposing that you do keep them all going for five to seven years,7 there is absolutely no guarantee that you're going to wind up with anything particularly special. But if you really want to know, there's some basic information about growing Phalaenopsis from seed here.
The most practical method for home propagation is still not incredibly practical, but: plantlets, called "keiki,"8 sometimes form spontaneously on the flowering stem of a plant. This can also be induced, sometimes, by applying a cytokinin (a plant hormone) paste to the dormant nodes on a flower spike. When a keiki has grown some substantial roots, two inches long or thereabouts, and about three leaves, then it can be removed from the parent and potted up separately. Keiki can also be left on the stem; given enough time, they'll flower while still attached to the parent plant. More specific information about keiki can be found toward the bottom of this page.
GROOMING: Phalaenopsis will need repotting every year or two, if everything's going well. There are a lot of prepackaged orchid mixes (the one we used at work contained various species of bark, sphagnum moss, charcoal, and perlite) out there; I think sphagnum by itself works pretty well for smaller plants, but for larger ones you do probably want something a bit chunkier.9
Actual grooming of the plants is fairly minor; you'll need to pick up dead flowers occasionally, and leaves drop once in a while, but there are usually not enough of either for grooming to be a major project.
After flowers have bloomed and drop, the spike itself can produce additional buds and new flowers, if it's still green and healthy-looking. The way to force this is to cut off the spike below the last blooming node; the new top node will, if conditions are favorable, produce another spray of flowers. This sounds like a great thing, but there's one substantial catch: it drains enough of the plant's stored energy that subsequent blooms will be smaller and fewer in number. For a very young or weak plant, doing this may deplete it enough that once you've run through all the nodes on the first one, you'll have to wait a very long time before the plant gets it together to bloom again. It could also weaken the plant enough to leave it susceptible to disease or pests. Consequently, this is best only attempted on well-established, large plants, and you're probably best not to force a new set of flowers more than once or twice.
On the up side, if the spike doesn't dry up and die, the plant may still produce a second round of flowers from that spike, all on its own, in which case you may as well assume that it knows what it's doing and let it.
FEEDING: Oh my god. Fertilizer instructions for Phalaenopsis are almost impossible to summarize, because every site I looked at had different ones. People recommend NPK ratios of 1:1:1, 3:1:1, 1:3:2, and 2:1:2. They recommend half-strength dilutions, and quarter-strength dilutions. Some say you shouldn't feed when the plant is blooming; other sites say to feed year round. Some people swear by adding a teaspoon of epsom salts (magnesium sulfate) to a gallon of water and watering with that during the one particular time when you want to initiate a bloom spike. I also saw recommendations to dilute your fertilizer more if you're growing in sphagnum moss than if you're growing in bark, though they didn't explain why there would be a difference.
Some of the variability in instruction could be because a plant's nutrient needs depend on its ancestry, so different methods may work better for you if you're growing some hybrids than if you're growing others. Perhaps a phal with a large percentage of Vietnamese genes wants subtly different things than a phal with mostly Phillippine ones. Or possibly it really doesn't matter that much. I mean, there may be no actual "right" answers here.10
So I don't even really know what to tell you. Some stores carry fertilizer which is supposed to be specifically for orchids. It's usually a small bottle, and has an NPK breakdown of like 3-9-6 or something. This is probably about as good an option as any, if you only have one orchid and aren't going to need to be feeding fifty plants at a time. Getting a more concentrated fertilizer and diluting it down yourself is generally more economical, but it's also (barely) more work.
I personally feed with a 14-14-14 time-release Osmocote formulation, and probably not enough. (I throw in maybe two or three of the little balls every three or four months, because I'm scared that if I use more than that I'll burn the roots.)
If you're trying to promote blooms, switching to a 1:3:2 formulation (like 10-30-20 or 8-24-16) for a brief period may help. Or it may not. I've seen a lot of discussion about whether or not high-phosphorous fertilizers are useful for inducing blooms, and everybody seems to make logical sense, but they also all contradict one another and I don't know whose logic to trust.
Feed less often during the winter, or when there's a long run of cloudy days, or when growing in cooler temperatures. Accordingly, feed more often in summer, bright light, and warmth. This is pretty much standard for any plant, though.
In an ideal world, you'll know a more experienced grower who has the particular cultivar you own, and you can just ask him/r about feeding. In this world, I'm inclined to say pick something simple, and if it doesn't appear to be working then try playing around with strength or NPK ratios or epsom salts or whatever.
So that's what I was able to find about caring for Phalaenopsis. It doesn't sound so hard -- in fact, one of the more annoying things about writing this profile was that almost every single site I ran into assured me that these were very, very easy to grow and bloom, so easy that anybody can do it. Yeah. Okay. Except not: all the sites that said phals were soooooo easy would, in the next sentence, turn around and warn not to water at night, lest root rot set in, and not to give them too much light, lest they scorch. And these sites were all prescribing specific temperatures at specific times of day and year, making impossible-for-most-people humidity-and-air-circulation demands, contradicting one another in really specific ways about fertilizer, and just kind of generally doing everything possible to make them sound really weird and touchy.
And then they brightly sum up with a big rah-rah Phalaenopsis are wonderful! Anybody can grow them! kicker, which, you know, talk about sending mixed signals.
Ultimately, I think the mixed signals are kind of appropriate, and how difficult you find Phalaenopsis is going to be somewhat a matter of perspective. If your point of comparison is whether you can treat one just like your Dracaena marginata, then you will in fact find phals to be kind of a challenge. If your interest in growing phals is to produce huge, perfect, florist-quality blooms, then you're going to have a rough time at first. But the actual work required is pretty similar to other houseplants: they need water, light, warmish temperatures, humidity, and fertilizer, like most everything else. My trouble with them has been, mostly, that the set of intuitions required for growing phals well is different from the intuitions required for growing most of my other plants, so I do the wrong thing semi-regularly, even still, and the plant suffers for it. So, bottom line, are they easy? Kinda. But also no. But mostly they're simple. Except when they aren't. Am I being clear?
Way more references than you care to read (probably):
Prior PATSP posts portraying plentiful pretty Phalenopsis portraits.11 (A few of these were recycled for use in the Phalaenopsis profiles.): (1) (2) (3)
Photo credits: mine except for the keiki photo.
1 (I don't watch these shows so much, but the husband does.)
Phalaenopsis appear to be used in interior design because they're brightly-colored, they hold on to the flowers long enough that you can reuse them from show to show and not have to buy new ones for every shoot, and they're tough enough that the designers can place them wherever in a room and they'll still do okay, they're not going to freak out and drop all the flowers or something.
It might just be that phals are trendy plants right now, though. I mean, HGTV never seems that interested in the plants. I get the impression that from an interior design perspective, or at least from the perspective of an HGTV designer person, there are exactly three kinds of plants: orchids (mostly Phalaenopsis), palms (I'm too palm-blind to identify any particular species being used, but decorators can't live without them), and cactus (which are usually not actual cactus: I mostly see Aloes).
2 (Less plausible now that I have the watering station in the plant room and no longer have to water all the plants in the kitchen sink. And not that I would anyway. Just, you know, if it happened, I wouldn't be heartbroken about it.)
3 Called pseudobulbs, from the Greek pseudo-, meaning false, and the English bulbs, meaning bulbs.
4 Some growers somehow manage to pull off growing Phalaenopsis in soil, which I do not recommend trying in the home at all. If you've bought such a plant, take it out of the soil as soon as you can and replant it in something that will breathe better, like sphagnum, bark, coco fiber, or some combination of these. It's not unheard of for the growers who do this to cover the soil with a thin layer of bark, so if the pot feels heavier than bark ought to, dig around a little.
My guess is that plants being grown in tropical climates dry out fast enough that soil isn't a problem, and soil no doubt ships better than bark does -- I've knocked my own bark-planted orchids out of their pots a number of times, just in the course of trying to water them, so I can imagine it's much worse when you've got a bunch of plants in a tall, mostly empty box (orchids are generally shipped in bud, so you need room for the flower spikes: this leads to boxes that are mostly empty space). But still.
5 At work, we would drag all the orchids outside during the summer, and then leave them out until the low temperatures were forecast to be below 40F/4C. I do not necessarily recommend this for the reader, but it's what we did. This probably sounds colder than they actually got: the orchid spot at work was under a lath house and under a couple large trees, and was in a city besides, so the orchids probably all stayed a few degrees warmer than the official low temperature.
This was partly because the later we let them stay out, the more time we had to try to move stuff around in the greenhouse to have room for them.
So, so much of my time in that job was spent on rearranging plants in hopes that space for new plants would magically appear once I'd done so.
6 (Even here in the Subjunctive Botanical Gardens, humidity dips below 50% pretty regularly. If it's been a while since I watered stuff in a given room, it's not unheard of for the winter humidity to get down close to 25-30%, even.)
7 Not a minor thing at all: Phalaenopsis seed pods may contain thousands of seeds. Most of those won't sprout, or will succumb to fungus, or something, but still, even if a tiny, tiny fraction of the possible plants survive, you could still be looking at twenty plants, and that's a lot of work, just from a single cross.
In the original Hawaiian, the singular and plural are the same (one keiki, two keiki, etc.), as in English words like "fish," "sheep," "reindeer," etc. As the word becomes adopted into other languages, by people who may or may not be aware of its treatment in the Hawaiian, one may see the form "keikis," as well as plurals that aren't even correct in English, like "two keiki's."
The terminal -s would be redundant and wrong in Hawaiian (like a native Hebrew speaker pluralizing the English "deer" to "deerim," using the plural suffix from a different language), but all kinds of things happen to words when they move from one language to another, as the speakers of the adoptive language regularize pluralization, conjugation, declension to that of the new language, so I'm not sure whether it's necessarily incorrect to say "keikis." It is, though, more respectful to the Hawaiian people and language to use "keiki" for both, even if it's not the usual English plural, so you may as well.
9 Small wads of fresh sphagnum dry out fairly evenly, but larger, or older, wads don't so much. So a large orchid in a bunch of sphagnum is likely to wind up in situations where the center of the root ball is wet, but the outside is dry, tempting the orchid owner into overwatering, rot, and plant death. Decently-sized bark chunks can't pack together well enough to block airflow to the base of the plant, so it will dry out more evenly. The specific medium doesn't necessarily matter as much as that you water appropriately for whatever it is, and that you change it before it breaks down and collapses around the roots, which both sphagnum-based and bark-based mixes will do over time.
10 As a rule, I assume that if advice about a particular plant varies considerably from person to person, that probably means it doesn't really matter that much how you do it. If it made that much of a difference to the plant, then everybody would do it the same way.
11 (I realized I had some alliteration going and ran with it. It doesn't mean anything in particular.)