Saturday, January 28, 2012

How to grow Phalaenopsis - an orchid blog "meme"?

Phalaenopsis driving you batty? Read on!
Like so many people, my first orchid was a Phalaenopsis. I had seen these amazing flowers for a few years and eventually, whilst on holiday in Switzerland, decided I had to have one. I bought my first from a florist in a shopping centre (in Lucerne I think). It travelled back across Europe in the foot-well between my legs, and graced the top of my fish tank in London until I went to university, where it met a sad and untimely death after the end of the first term, just under a year into orchid-owning*.

I've noticed that sooner or later, every orchid blogger seems to get around to posting their "How to grow Phalaenopsis orchids" notes. It's so prevalent, it almost counts as an Internet meme, along with lolcats and the like...! Here's my stab at it, prompted by my mother and some other friends of mine acquiring some of these plants and asking me, as the "person who does orchids", how to care for them.

One of the fantastic things about Phalaenopsis is how long the flowers last; I've had one that's been in more or less continuous bloom for what seems like at least a year; flowers typically last 1-3 months at the very least. The range of colours available in the hybrids you'll see today means you should find one to fit your home, no matter what your decor scheme might be!

There's something of a debate raging in the orchid world. Are Phalaenopsis (commonly called "moth orchids") the perfect "beginner orchid" or not? I'm on the "yes" side of the debate, and outlined below is how I think most people will wind up being fairly successful with these plants. There are of course a few places where you can run into difficulty - I'll cover those a bit later.

Too much light? Net curtain, to the rescue!
Under African skies, even this would be too much light
for Phalaenopsis orchids (it gets direct sun).
Phalaenopsis don't need nearly as much light as many plants. A bright-ish windowsill with no direct sunlight will work well for them - the key is they really don't do well with direct sun, which will scorch the leaves - they'll survive too little light for longer than they will too much. Indeed, if you're successfully growing African Violets, you should find Phalaenopsis do just fine alongside them. If you have access to a fancy camera or a light meter, you can work out how many foot-candles of light your proposed spot has; one of my earlier "Gadget Posts" covers methods you can use to work out light intensity. Phalaenopsis are reported to like 1,000-2,000 foot candles of light. If your windowsill has too much light, you can either move the plant a little further away from the glass, try another window, or diffuse the light a little with some net curtain or similar material. In the unlikely event you have too little light, a fluorescent bulb should provide all their needs.

Many orchid growers will tell you that the colour of the leaves will tell you what the orchid thinks of the light levels; in general, a nice bright green colour means the plant is happy; pale or reddish (plant sunscreen!) means too much light and very dark green not enough. Phalaenopsis aren't that fussy though - any bright, indirect light should be fine.

Phalaenopsis are generally quite tolerant of water quality (dissolved minerals), so unless you live in an area where the water supply is quite brackish, virtually any water out of a tap will do. Of course, if you have access to rain water or reverse osmosis water, it's generally a good idea to use it as it helps your plants along (see under Fertiliser, below). 

One thing everyone wonders is when and how much one should water an orchid; there is no hard and fast rule other than "when it needs it"! Much like with everything else in orchid culture, err on the side of "too little" if you're not sure. Orchids are survivours, but don't tolerate being spoilt well!. Too much water is perhaps the quickest way of killing them. On average, most Phalaenopsis in the home want to be watered about once a week, but if your conditions are colder/warmer damper/drier this will change, and may change throughout the year. The best way of watering orchids is to take them to your sink and really give them a good soak through. As an alternative to this, I also quite like to leave the bark soaking in water up to the lip of the pot for about 20 minutes to make sure the bark is really saturated. I tend to let the pot dry out between waterings.

It's generally a good idea to water in the morning, giving the whole day to dry out, rather than risking a damp plant rotting in the cooler night air. Also be careful not to get water into the crown (the part of the plant in the middle of the leaves) as this often leads to "crown rot" which is deadly - if you do inadvertently get some in there, either blow it out or blot it up with some tissue paper. If you're wondering how an orchid that gets water on it can survive in the wild where it inconsiderately rains all over the plant, most of these plants naturally grow with the crown facing downwards, so it naturally drains out!

If your Phalaenopsis has lots of aerial roots (roots that stick out of the pot into the air, rather than going into the bark), you may like to periodically (daily in warm weather) mist them with water, making sure not to get too much water on the leaves or making the bark too wet. 

Some Phalaenopsis are sold with instructions to water it once a week by placing an ice cube(!) on top of the potting mix. Don't, because these orchids hate cold water, and an ice cube isn't really enough water.

It's generally best to feed orchids very lightly, but regularly (i.e. once a week - "weakly, weekly"). Orchids in general need a lot less fertiliser than other houseplants. Generally, half to quarter strength fertiliser is a good rule of thumb; if you get specific orchid fertiliser, usually the instructions on the packet should be right, but feel free to go more dilute. Depending on your conditions, you may find that fertiliser salts build up in your medium, making it more and more salty to the detriment of your plant; you can avoid this by watering with pure water once a month; it's best to water the plant, wait 20 minutes, and flush it through with more clean water (no fertilisers) to make sure you really leach out anything which has accumulated.

The purer your water, the more fertiliser you can give your plants.  If you have access to an EC meter, you can figure out exactly how much fertiliser to add to your particular water. Phalaenopsis orchids can take quite a lot of fertiliser - up to 800μS/cm, although generally I'd suggest using a little less than that so you don't subject the plant to too much osmotic stress! Essentially, impure water has salts in it that aren't usually fertilisers; if you start with pure water, a larger part of that 800μS/cm can be fertiliser instead of just tap water! As an example, when we were having a bit of a drought last year, our tap water was around 669μS/cm, leaving only a little bit of "room" for fertiliser! In fact, going by conventional wisdom on how much fertiliser I should have been using, I was making the solution too strong, and my cymbidiums leaf tips started to go brown/black (they stick excess salt in the tips of their leaves as they have no other way to excrete them). Swapping to reverse osmosis water has made a big difference to the plants; the RO water I usually use generally has a conductivity of less than 10μS/cm, which means I can add quite a lot of fertiliser to the water.

Phalaenopsis orchids come from the tropics. They like warm temperatures, but in general, they're quite happy at "normal" human living temperatures - min 10ºC, max 30ºC, preferring the middle to upper parts of this temperature range when in active growth. Studies indicate that they need a drop in temperatures (to around 12ºC/55ºF) for a couple of weeks to initiate flower buds - this is probably why most of us rebloom these orchids in winter or early spring. If your house thermostat isn't set that low in the winter, that may be one reason you find your plant won't rebloom! They also appreciate a fair amount of light if they are to bloom. The critical temperature seems to be about 27ºC, above which the plants will not spike. Keeping the plants hot and dark (50% shade) generally prevents flowering - a trick commercial growers use to time their flowers - once they want the plants to bloom, they keep them cooler and in brighter light, and hey presto, flowers!

Phalaenopsis orchids prefer a fair amount of humidity in the air (around 70%), but will adjust to most households quite happily; if your air is really dry, they'll appreciate having their aerial roots misted.

Caveat Emptor
For those who managed to avoid learning any Latin, this means "Buyer Beware". There are a few things you should check when you buy or receive a Phalaenopsis orchid.
  • Killer Moss
    • Many Phalaenopsis are grown in sphagnum moss by large commercial greenhouses. If you bought a fairly cheap orchid at a supermarket or other non-specialist orchid seller, chances are very good your orchid is in moss. This is a good medium if you know what you are doing, but not for most growers; indeed, such plants are grown to be disposable - the plants often need repotting when they are sold to you, but aren't and then suffer.
      The trouble with moss is it tends to keep the roots too damp, they suffocate, die and rot. Shortly thereafter, your plant looks sad and keels over, dead. If you're into extreme measures, you may be able to rescue an orchid that's reduced to this state with a technique called Sphag 'n Bag.
    • In general I would thoroughly recommend repotting Phalaenopsis orchids into a bark-based medium a soon as you can; these orchids are unusual in that they don't usually sulk too much or drop their flowers if you repot them. There are good videos online that explain repotting.
  • Bugs
    • Before you buy an orchid, make sure there are no pests on it (aphids, scale, mealy bugs, mites etc.); it's generally a good idea to leave the plant where it is if it's sick; you don't want the additional headache of dealing with the infestation, or worse, having it spread to your other plants. If someone gives you one, inspect it carefully, particularly under the leaves, around the flowers and where the leaves meet the main "stem". 
  • Good roots
    • A lot of Phalaenopsis orchids are grown in clear pots. This is very handy as it means you can check on the general health of the roots any time you wish. Healthy roots are covered with a layer of whitish cells called "velamen" with a green/green-brown growing tip. If the velamen is very wet, it will look green as you can see the green tissue underneath when it's damp. Unhealthy roots are black, brown and/or mushy, and should be cut out. If you're going to buy one, it's worth checking there are still some good roots there by having a careful look through the pot. Avoid any that are wobbly in the pot as they're almost certainly having trouble with their roots!

What do I do when it finishes flowering?
Eventually, your Phalaenopsis will drop its last flower. You have two options 1) cut the flower spike (the "stem" the flowers were growing on) off; or 2) trim the spike about 1cm above the 3rd node from the base of the plant, as seen at 30 seconds into this video. If you trim it, you'll often find it encourages the nodes to put forth another flower spike for yet more blooms; however, there will be fewer of then and they'll generally be smaller than the original spike. Some people suggest that cutting it off is better, as it lets the orchid have a "rest" from the energy requirements of producing flowers - meaning the next time it puts out a brand new spike, it will have that much more oomph to give you really great flowers.

I'm (an)NOID?
Forgive the poor attempt at a pun (which has been made before). As you float around the orchid Internet, you'll see mention of "NOID" all over the place. NOID simply means that the hybrid ancestry of that particular orchid is unknown (or uncertain). With well over 100,000 orchid hybrids having been registered (and presumably many, many others made but not registered) it's hard to be absolutely sure if your plant that looks like *this* really is that-other-plant-that-looks-very-similar, or something else entirely. Unless it came with a tag that says what its parentage is, or gives a hybrid name, you have a NOID. Most orchids you buy from supermarkets, florists and other non-specialist orchid-sellers will not have a label with the precise name of the plant. That doesn't mean you can't enjoy it! 

I want to know more
Visit this thread on OrchidBoard to learn more about Phalaenopsis and how to grow them.

I have too many Phalaenopsis and I'd like to try something else...
Suffering from YAP? Need a change? Assuming you're growing it in your house, why not try a Paphiopedilum? Many hybrids, particularly the Maudiae types, are quite amenable to house plant growing conditions!

Hopefully, this will arm you with sufficient information to successfully grow these lovely orchids - but beware, they're often the "gateway drug" from simply owning a few houseplants to full on orchid-mania. Indeed, Phalaenopsis themselves may cause an outbreak of YAP (Yet Another Phalaenopsis) in your life!

I'm thinking I could perhaps expand this into a series of posts as I learn more about various types of orchids - perhaps (Orchid X) For Noobs? Let me know if you think this is a good idea, and what you'd like profiled :)

*My first Phalaenopsis died because a friend I press-ganged into looking after it for me when I went on holiday to visit my family who had moved to South Africa forgot to take it home with him over the Christmas holiday. About 6 months later, we found it, brown, sad and dead in the cleaner's closet.