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

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.