Water Culture for Phalaenopsis

[ In case you don't read the whole post - I ended this experiment after 5 weeks when all the roots on one of the plants rotted. And I mean ALL, see photo at the end. The other two plants weren't quite as bad, but they appeared to be heading the same way, so I stopped the experiment with all of them. As several others have found with their experiments (which I knew about and ignored), do NOT USE water culture, or use at your own risk! Despite my elaborate rationale, which I have left intact below, clearly this is not a good plan, or at least not the way I did it. Yes, Phalaenopsis are not aquatic. I should add that this experiment does not rule out the possibility that new roots would be better adapted for growth in water, but I elected to save my plants. ]

Photo from http://www.phals.net/honghenensis/honghenensis-in-situ 

I have had three Phalaenopsis hybrids for many years, and they have done fine in the usual mixed bark planting medium, but I recently decided to try them in water culture. I will report on how the plants do over time. I don't know how generally pure water culture will work for orchids - probably not well for most. Growing in inert media such as sponge rock, expanded clay, or charcoal seems to work fine for a wide range of epiphytic orchids, but the water/air/root dynamic under those conditions is much more like traditional media.

I got started with the idea of water culture due to one Phalaenopsis hybrid in my work office, where humidity is very low. I was growing it cased in a sealed pot sitting in a shallow bowl of water, hoping to keep local humidity up a bit, and as it grew aerial roots I started tucking their ends into the water hoping to keep it happy. The roots clearly loved being in the water - they grew fast and they looked fat and sassy and they were bright green. The plant thrived. Yes, it is a grocery store hybrid Phalaenopsis (i.e. only my friend Theresa is capable of killing it) and most of the plant is still in bark medium in a pot, but the idea germinated of tossing the pot and growing in a bowl of water.
Look at the roots in the in situ photo, photographed in situ in mountains in Burma growing low on the trunk of a tree (the roots are the silvery green ribbons plastered all over the bark). This species of Phalaenopsis has very few leaves and apparently does much of its photosynthesis with its roots. Most Phalaenopsis species have more leaves but they all have light-exposed greenish roots, and a few species are leafless or seasonally leafless. Their roots provide most or all of the photosynthesis. Growing Phalaenopsis mounted directly on tree bark is most natural, but it isn't convenient unless you happen to live in the right place or have a greenhouse and are willing to wet them every day.


Back at home with my test plants: the containers I am using for my full water culture trial are glass bowls that are approximately spherical with a slice off the top of the sphere. This sort of vase is relatively easy to find on-line - a search at [a certain large retailer named for a South American river] for "glass bowl vase" finds them readily. The idea is that the narrow mouth will support the plant and keep the humidity inside the container high and the clear sides will allow the roots to green up and become photosynthetic, which is the natural condition of Phalaenopsis plants in the wild. The broad leaves of the plant rest on top of the vase and the entire plant body and most of the roots are not immersed. The roots would never naturally grow under water, but keeping the water very shallow will hopefully keep them well aerated. The base of the plant stem is at least 5 cm from the water and it is dry. The root core presumably transports water up the leaves but the root velamen is dry to the touch above the water line. I will be surprised if I have a problem with stem rot as others have reported for their tests. The setup I am using would be harder to arrange for plants with different shapes, but for Phalaenopsis in the right sized bowl they just sit that way naturally.

Phalaenopsis unknown hybrid day 1 (5/11/2017)

I am using a rather small amount of deionized water in the bowl (about 2 cm deep) with a bit of complete fertilizer added (the kind designed for pure water - it has calcium and magnesium and all the trace elements in addition to all the usual stuff. Don't you just love that plants require molybdenum? What!?). Tap water is probably fine too as long as it doesn't have a lot of dissolved minerals. I dump the water out for a day or two once a week, as various sources on the web suggest - the idea is to inhibit too much bacterial and fungal growth and to mimic occasional dryness in nature.

The photo above is one of my plants, for which I am keeping a photographic record. This plant just came out of bark medium and you can see that most of the roots are bone white, with only a few green bits - the parts that were aerial when potted. Two weeks later, as I write this post, the roots are already getting a pale green blush - I will update or make a new post when the difference is more obvious. So far no roots have died.

As a side note, it is interesting that the natural plant (above) is growing "sideways" - from pictures and comments I have found on the web, this is usual for Phalaenopsis, and quite often they grow slanting downward or even completely upside down (how the seeds stick and germinate on the bottom of a branch I don't know). This explains why culture guides warn that you risk rot if you wet the growing crown of Phalaenopsis, yet natural rain doesn't present a problem. They don't grow right side up! Um well, we don't grow them right side up.

And ... experiment over because here are the roots after 5 weeks (I cut them off as they rotted one by one, but I stuck with it to the bitter end). You can't see the plant leaves above, but this is the same plant - I just moved it temporarily to rescue spaghnum moss and my experience is that it will recover without much trouble because it is a Phalaenopsis hybrid and they are tanks. If you look closely you can see one new root tip, which started while still in water culture.

Same plant on 6/17/2017

Cheating Orchids (Flower Mimics)

In an intelligently designed world (which ours is not), every flower would offer a reward to its pollinators - you scratch my back and I'll scratch yours (technically called mutualism). Why else would a pollinator be willing to visit flower after flower, inadvertently transferring pollen?

Many orchid flowers violate this sort of reciprocity using a variety of tricks, famously including forming insect mimics to induce insects to attempt to mate with the flowers. I recently read about one trick I hadn't heard of before, at least among orchids (reference below). Two different orchids, Cymbidium insigne and Dendrobium infundibulum, appear to mimic a Rhododendron flower, allowing them to get away without offering the usual nectar reward. The Rhododendron (Rhododendron lyi) and the two orchids have the same range in mountains of northern Thailand. They bloom at the same season and all three are visited by the same bee species (Bombus eximius). The flowers of all three appear quite similar (photos below - they aren't hard for us to tell apart but remember they only have to fool the bee). But only the rhododendron flower produces nectar! No direct proof has been published, but it is likely that both orchids have evolved flowers that are similar to the Rhododendron and have been able to forego the metabolic cost of producing nectar. As long as the Rhododendron flowers are more common than the orchids, this sort of mimicry is thought to be feasible.

The orchids are cheaters and, as long as the Rhododendron and the bees are around and the bees don't catch on, they will no doubt continue their cheating ways. There is risk for the orchids - if the bee or the Rhododendron go extinct the orchids may be doomed as well. These sorts of interdependencies are common in nature, especially in stable warm climates. Evolution does not plan ahead.

It would be interesting to know if a minority of the orchid flowers still make a little nectar (even rare orchids making a very small amount), or if the ability to make nectar has been lost completely (as humans completely lost the ability to make Vitamin C during a period when our ancestors ate mostly fruit). If nectar production is still possible, then the orchids could probably survive loss of the Rhododendron flowers - natural selection to reward pollinators would kick in again and orchids that make more nectar would gradually increase. For we humans, the genes that encode Vitamin C synthesizing enzymes are completely dead (technically called pseudogenes) and without technological intervention we will never make Vitamin C again.

Rhododendron lyi (photo by Marc Colombel)

Dendrobium infundibulum (photo by Marble Branch Farms)

Cymbidium insigne (photo by Simon Pugh-Jones)

Gosta Kjellsson, Finn N. Rasmussen and David Dupuy Journal of Tropical Ecology Vol. 1, No. 4 (Nov., 1985), pp. 289-302

A Brief Primer on Orchid Names

Orchid naming can be baffling at first, but it really isn't all that complicated and all the little rules are important for keeping all the types straight. There is a remarkable volume and diversity of nomenclature butchery out there on the World Wide We-Are-Clueless, so be aware that these are the rules as they should be, not as they are used by others.

I will give the rules by example:

Cymbidium ensifolium - genus and species, should be italicized but that isn't that important and I will omit the italics below. Genus name should always be capitalized, species name should never be capitalized. These are the orchids that occur naturally in the wild and their genus/species name is part of the general biological naming and classification system first codified by Carl Linnaeus in the early 1700s. Because there is always some genetic diversity within a species, not all plants will appear identical, but they will likely differ only in a few specific traits. For historical reasons, there are often species synonyms. Cymbidium ensifolium has about a dozen other names according to IOSPE (Internet Orchid Species Photo Encyclopedia), but it has a particularly long and confused history and thankfully it appears everyone now calls it Cymbidium ensifolium.

Cymbidium ensifolium var. alba - a variety of the species with some particular trait difference, in this case white (or at least whiter) flowers. Not all Cymbidium ensifolium var. alba plants will necessarily look the same - often a similar variation is discovered multiple times. If they are close enough in appearance they may get the same variety name. Sometimes var. is omitted or replaced by subsp., subvar., form, forma, cv. (short for cultivar), or other doodads, all of which have slightly different meanings that we can happily ignore because in essence they all mean "variety". [Apparently botanists would rather squabble about minutiae than spend their time crouched in a dripping wet cloud forest for days on end, picking off slugs, swatting gnats, and watching a flower to see who visits it and how often pollinia get stuck to the visitor. I wonder why.] A species name is always one word (although it can be hyphenated), so if there appear to be two species names then the second word is actually a variety, e.g. Cymbidium ensifolium alba with the "var." omitted. 

Cymbidium ensifolium 'Jin Chi' - the single quoted text specifies a named clone of the genus and species. All plants with this name should be genetically nearly identical - either divisions of the original or mericlones derived from meristem cells from the original. This particular clone has variegated leaves and a particular flower form and color. If you want to be certain you will get exactly what you expect, purchase named clones.

Cymbidium Sandy Tiger - a named hybrid (no quotes) between two or more species from the Cymbidium genus. Unlike species names, hybrid names are capitalized, never italicized, and may be more than one word. This particular hybrid is from a cross of two species: Cymbidium sanderae x Cymbidium tigrinum (called a primary hybrid). Other hybrids may be from crosses among other hybrids, but they still get a specific name, such as Cymbidium Autumn Green (a hybrid with more than two Cymbidium species contributing genetic material through a series of crosses). If the hybrid has no registered name, it may be identified by the two parents, e.g. Cymbidium tigrinum x Cymbidium Autumn Green.

Cymbidium Autumn Green 'Geyserland' - a named clone of the hybrid Autumn Green, just as with 'Jin Chi' above, except this clone is a hybrid plant rather than a natural species.

Hybrid names like Sandy Tiger and Autumn Green are registered with the proper authorities (aka the nomenclature nazis) and in the future all hybrids with the same parentage are supposed to get the same name. As with species, hybrid plants with the same name may not all look the same but they will tend to look quite similar.

There are also registered hybrid *genus* names, such as Rhyncattleyanthe, used when a cultivated hybrid involves species from more than one genus. You can think of these as being just like a genus name and not go far wrong. In any case, genus names for the entire orchid family are frequently revised so the hybrid genus names change too.

If you see capitalized acronyms at the end of a name (e.g. AM/AOS) those are awards given to the plant, not part of the name itself.

Those are the main points. There are many finer points, such as using abbreviations for genus names, but most of the differences you will find out there are just people who don't know how to use the names properly. Or don't care. Usually both.

It can be a bit complicated, even annoying at times, but there is some sense to all this. The idea is to keep track of the genetic heritage of all the plants being grown. If this doesn't matter to you, then just call your plants "Big Boy" or "Pretty Girl" (even though all of them are both boy and girl!) and ignore all this stuff. I won't report you to the authorities. 

Orchidarium 2

A humidity tray for the bottom and part of the grape wood burl in a temporary position... it is starting to come together! I also have an improved plan for cooling. I thought about using a Peltier cooling plate mounted hot out/cold in but I would prefer to avoid that if possible because it will add clutter and complexity (it would require two radiator heat sinks and two muffin fans, making quite a stack altogether). Instead what I will do is have an additional small muffin fan pointing down into the tray (which is filled with water) and it will be wired to the same thermostat that controls the vent fan. When the temperature gets too high, the vent fan and the tray fan will come on - room air is pulled in and extra humidity is added at the same time. Simple!

If one wanted to do a cool case, the Peltier set up should work - they can pump a lot of heat. The set up isn't all that bulky. Peltier cooling is not very efficient compared to compressor-based coolers but they are quiet and compact so if the cooling demands are modest they are a reasonable choice, and the parts are inexpensive because they are used a lot for computers.

Oh dear, now I am getting the urge to build a cool orchidarium. There are so many little gems I can't grow in the current intermediate case. This hobby is addictive. Lots of orchids grow in "cloud forest", very high in mountains in wet tropical areas. I once visited a cloud forest in Costa Rica and the habitat is strange - never very cold but never warm and very very very wet. Daily downpours in the wet season, and not that much less in the "dry" season, with frequent heavy cool fogs. While I was there, the surface of everything was wet all the time. Not damp - wet. You are best off keeping your camera in a plastic bag with desiccant.

Orchidarium 5/30/2017 - the light at the top left is a reflection from the room.

Windowsill Orchids

The most common and probably the easiest windowsill orchids are the lovely Phalaenopsis (rhymes with "shall a mop kiss") hybrids you can probably find at your local grocery store or floral shop. There are guides for growing these beauties all over the web, and I will not add to them. If you live in the right climate, there may be a range of plants you can grow conveniently outdoors or combined with the windowsill. Here I cover only orchids that should be able to adapt to any reasonable home environment year-round (if you use air conditioning a lot, you will need to add a humidity tray or a humidifier). If you poke around, you will often find detailed culture guides for various orchids. The plants I list here do NOT need any special care beyond not letting them get bone dry and flushing the pot with water over a sink instead of the usual houseplant dribble-on-the-soil-surface method of watering. You can supplement with a bit of fertilizer now and again, but orchids are adapted to very low nutrient conditions and it is easier to over than to under fertilize.

If you have successfully rebloomed a Phalaenopsis orchid (not the flowers it came with, the ones several months later that indicate you kept your plant happy), you might be interested in getting a taste of the diversity and seductive strangeness of other orchids, but you aren't sure where to get them and which will work well for windowsill culture. Here is your guide! Or at least the ones I know about and remember to write down. If you are one of those people who buy an orchid in bloom and then let it die, then repeat... you are a cruel orchid taskmaster and you should be thrown in jail. And what are you doing reading this page anyway!?

First, my experience with mail-order orchids has been almost uniformly good - these outfits are usually small and run by people who care about orchids. They aren't cheap, but this is because orchids are slow growing and require greenhouse care in most climates. I won't endorse any particular site, but if I find one that I have had a seriously bad experience with I will post it here. Some plants I got from Orchids.com were potted poorly in ancient packed down spaghnum, but even they were acceptable (note - Orchidweb.com is an entirely different outfit from which I have received excellent plants). Any plant commercial sites list as "intermediate" or "warm" and "easy grower" is a good bet for the windowsill but do check that you can meet the light requirement. I do recommend getting a good hand lens (10x to 20x is most versatile) and inspecting every new plant carefully for scale, mealybug, aphid, or spider mite infestation. Concentrate on the underside of leaves. Adults of all three pests are visible even at 10x, though spider mites will look rather small. If you find a problem, quarantine and treat aggressively to prevent spread to other plants. Greenhouse operations can't do this sort of detailed inspection of every plant; I assume they rely on spot inspection, signs of problems apparent to the naked eye, or scheduled pesticide application, and trust me - you will sometimes catch things they missed. How to treat is up to you, but I can warn you that my experience with "environmentally friendly" treatments is not positive. If there are more than one or two pest critters I reach for the big guns because, unlike the pests, I have no plans to eat my orchids.

If you live near a major metropolitan area, chances are there is a specialty orchid retailer nearby - give them a visit for advice and plants, but keep in mind that they will usually stock a small sampling of orchids because there are far too many for any one retail site to keep. Regular garden centers will usually have only Phalaenopsis and maybe a few others.

Okay, the plants. For all of these, you can readily find many pictures on the web... copy and paste, copy and paste. I grow mostly species, but hybrids tend to be a bit easier to grow because they are often selected for vigor under conditions closer to your windowsill than the species experience in the wild.

For low light conditions (such as those preferred by your grocery store Phalaenopsis hybrids):

- more or less any Phalaenopsis hybrid or species and Sedirea japonica - they tend to have similar flower form but they vary a great deal in plant and flower size and flower color, and a few are intensely fragrant. Most of them also possess one of the more remarkable lip structures among orchids; get a hand lens and take a look - a complex 3-D arrangement of flanges, tongues, and curling wisps, often elaborately colored, all designed to guide the pollinator. The rest of the flower is just a big bright flag that says "Hey look at my lip!".
- most Paphiopedilum hybrids or species - these are in the group commonly called Lady Slippers, with large cup-shaped lips and often strange warts, hairs, brown or black spots, and glistening wet patches. They like to stay a bit wetter than Phalaenopsis but are otherwise culturally very similar. Paphs (as we orchid snobs like to call them) aren't always my favorite orchids, but they are easy to grow and they do have a certain lurid appeal. Often very lurid. Many people love them, probably people with hairy warts on their noses. I recently read on an orchid society web page that Paphiopedilums are "often regarded as the true aristocrats of the orchid world" (by whom!?). Though there are a few that strike me as regal (Paph. philippinense and the astonishing Paph. sanderianum), I would otherwise reserve that description for Cymbidiums or Neofinetia falcata. If all those warts and bristles turn you off, there are some Paphs that have more traditionally pretty flowers (armeniacum, delanatii, micranthum, niveum, vietnamense and their hybrids). Then there is Paphiopedilum bellatulum, with the "help me, I'm covered with leeches!" flower. Named clones of Paphiopedilum orchids are usually very expensive because they can't be mass-produced by mericloning.
- Haraella retrocalla (syn. odorata) - a tiny charming plant with outsized and interesting flowers. Very easy to grow and a perfect introduction to orchid diversity. The flower will not look anything like your idea of an orchid - more like a beetle with a fringe.


For higher light (but no direct sun except dappled):

- Cattleya hybrids - I am not so fond of the classical corsage Cattleya flowers - to me they look like big ruffly cabbages and they don't fit easily on a windowsill - but there is a variety of more recent hybrids with smaller neater flowers and growth habit that are lovely. Most are fairly easy to grow if you have lots of light (still no direct sun) and read a bit about their seasonal care. 
- Cymbidium ensifolium and sinense - most of the large Cymbidium hybrids commonly sold are beautiful but are not easy to flower without special treatment, but these species are more likely to flower on the windowsill. (Also look for hybrids marked as "warm tolerant".) These species are also smaller and have very handsome narrow blade-like foliage and all have a lovely fragrance. The flowers are not showy like the big hybrids but they have an elegance of their own. As a side note, there is an extract apparently made from Cymbidium goeringii that "increases energy". I am highly skeptical, although perhaps it contains caffeine or something of that sort. It reminds me of an old European myth that certain Orchis genus tubers affect male virility, presumably because they look like a pair of testicles (orchis is ancient Greek for testicle - you can't accuse botanists of being bashful). Look up the Doctrine of Signatures for many more amusing and absurd claims. Rhino horn is a good one (and if you can't guess what that is supposed to be good for, you really should get out more). Orchids of course get their name from the Orchis genus. So next time you show off your orchids, keep in mind that your effusive claims may translate as "look at my shapely testicles" or "you need a hand lens to see my testicles". Not to mention fragrance.
- Neofinetia falcata - small fan-shaped plants with exquisitely beautiful and sweetly fragrant white flowers. The species has a long history of cultivation in Japan, with the attendant range of cultural varieties, including different leaf shapes, sizes, and flower shapes and color. The plain species is just as lovely as any cultivar and probably easiest to grow and flower.
- Oncidium Sharry Baby or Twinkles - divinely scented and pretty little flowers in large panicles and easy to grow. Sharry Baby is large, Twinkles is smaller.
- Phaius tankervilleae - a large terrestrial orchid with beautiful flowers, probably better for the outside garden in warm areas, but can grow fine indoors if you have space.
- Zygopetallum hybrids and species - all of them are somewhat similar looking, but they are spectacularly beautiful in an odd jungly way and nearly all are fragrant. Fairly large plants.

Orchidarium 1

Apart from the many beautiful flowers for which they are most famous, orchids have other seductive charms compounded of their slow-motion lives, their amazing diversity, and often just plain strangeness. Flowers that look like bees, spiders, flying ducks, monkey faces, ballerinas, corkscrews, kissing slugs, rotting meat, abstract art, a Klein bottle, space aliens, and - my favorite of all - tiny furry toilet bowls (Stelis pilosa, syn. Effusiella amparoana). What more could you ask for?

I have grown a small number of orchids on a windowsill for years but recently began outfitting a Wardian case to grow intermediate temperature orchids that need more humidity. The picture below is the way it looks near the start, with three muffin fans near the top and a few plants sitting on the bottom. Air circulation is enough to make slender spikes and leaves wave gently in the breeze. Humidity is usually well over 80% but in the heat of summer I will have to leave the case open and it may drop to 50% or so at times. Plans include adding a vent fan which will come on when the temperature gets too high and possibly supplemental light when summer ends, as our winters are rather dark here in Seattle.

As parts come together, some plants will be mounted on grape wood burls (Blooms and Branches is a great source) and hung from wire screens. Right now the plants are all small to mini sized, mostly Pleurothallids, including Specklinia, Restrepia, Pleurothallis, and Masdevallia species.

In the future, I will post cultural and natural history information about orchids, including the amazing story of their evolution into epiphytes and their diversity and ingenuity in attracting pollinators.

Orchidarium 5/27/2017

Scaphosepalum breve bud