text and photos by Jeff Hale
I am not a savant. I have killed Geraniums. I am not even particularly lucky (the casinos love me)! This being said, surprisingly, I have been successful in growing and blooming the "Ghost Orchid" Dendrophylax lindenii. This year, to my amazement, seven flowers opened simultaneously. The nighttime fragrance is intoxicating.
I wanted to share what I have found works for me, as well as encourage others to not be afraid to grow these rare, endangered treasures. My ultimate goal is to see these reintroduced into the wild, and who knows, maybe someday we will see them get off the endangered species list.
Horticulture, like Medicine, is not an exact science. There are certainly many methods and techniques that will work based on your location and growing conditions. This is simply mine, and how I arrived at it.
FIRST A LITTLE HISTORY
I was a geek in the "Botany Club" in junior high, and our guest speaker was the local school superintendent. He spoke about his orchid growing hobby and brought a few blooming plants. This was in the early seventies. I was hooked. I acquired and grew my first orchid, a white Phalaenopsis, under shop lights in my parent's basement. This progressed as I grew into adulthood, eventually growing on my own windowsills and under lights as I moved from place to place. I got my own home and my obsession escalated. I decided the three tier light carts I had rigged up were making it difficult to fit guests into my dining room. Though I had no problem with it, most guests found the glare of the fluorescent lights distracting.
I needed a greenhouse. The problem was I did not have much space. You have to understand, I live only a few miles from downtown Chicago, on a small lot with the elevated train running just a few yards behind my home. I can wave to the passengers on the train from my second floor office - I no longer work in my underwear.
Eight years ago, I made a decision. I built a small 6' by 8' polycarbonate lean-to green house on my tiny side deck. This was an easy decision, since the roar of the train made it unsuitable for entertaining, not to mention the scent from the alley in the summer. It faces south, and gets direct sun for 6-8 hours depending on the season, and then the sun disappears behind the elevated tracks.
At first, the humidity (or lack of it) was a problem. Working out of a home office can be a blessing or a curse. I was a misting "junkie." Home most of the day, I could not keep my hand off the spray wand whenever I peeked into the greenhouse. I kept a wireless hygrometer in the greenhouse, with the receiver on my desk so I could run down whenever I saw that the humidity was dropping. I set up a mist system on top of that. It was disastrous. I rotted more plants than I would like to talk about. Controlling humidity in a small space can be perplexing.
Living in Chicago, you have about 4 months of particularly grey sunless days, often with several feet of snow. My winter experiment with a supplemental 400W high-pressure sodium light (on a moving light rail no less) was another catastrophe. I learned you couldn't grow orchids in an oven.
THE STORY OF MY SUCCESS
I realized that my small standalone humidifier was insufficient. When the temperature rises, humidity drops. As the vent opens (at 85 degrees) and the exhaust fan goes on, the humidity went out with the air. It dropped to 25% at times. I wanted high humidity without having to mist constantly. I had a bright idea. I purchased the largest stand-alone home humidifier I could from my local hardware store. I purchased a model that you can set for humidity in the upper ranges, as many models cut off at 50%. I drilled a hole and put a float valve in the reservoir. I then connected it to my water supply so I would not have to fill the 3-gallon reservoir every day. I set it for 65-70%. It is an evaporative model since the "ultrasonic" ones, when used with tap water, produces a fine mineral powder that covers everything.
I started using 35% shade cloth from March to October to help control the temperature. The Chicago summer can have temperatures of 50° F to 100° F plus. I added a small rotating fan at waist level to equalize the temperature and humidity.
I limited my misting to only two (okay, sometimes three) times per day, morning and afternoon. However, occasional trips for 4-5 days away from home with no misting do not seem to be detrimental. I started to mount more orchids on bark since I had good humidity and the temperature under control. I started to have success with many species that had previously languished. Vandas hung at the apex of the greenhouse bloomed and thrived. Brassavolas and Rhynocholaelia digbyana on mounts flourished.
Supplies and Materials for mounting Dendrophylax lindenii
I am fortunate to live near Oak Hill Gardens, one of the leading suppliers of Dendrophylax lindenii, as well as other hard to find species. Owners Greg Butler and his wife Liese are involved in day-to-day running of the business, and her father and founder, Hermann Pigors is involved mostly in the laboratory. They were one of the first to be successful in the pollination and cultivation of this rare plant, and making available to the public over ten years ago. Liese estimates they have sold "thousands." Liese also acknowledges there has been some success "mostly in Florida and the South."
On one of my trips there in 2003 to restock my greenhouse, (after one of the previously mentioned catastrophes), I purchased a small "plantlet" of Dendrophylax lindenii tied with fishing line to sphagnum moss. It was mounted on a stick. When I got it home, and untied it (I have a hard time with self-control), I discovered to my surprise there were three small plants, ranging in size from ¾ inch to 1 inch, each with two to three roots.
I read the blogs and discovered some information now I know to be erroneous (grow in the shade, dilute fertilizer, use only RO water, must be mounted on Madagascar magic wood, etc.). I tried a variety of methods over the years, some with not so great results. Growing in an aquarium with high humidity resulted in an algae covered mess. Cork bark did not give me good results either. I have RO/DI water due to one of my other obsessions, (Amazonian Soft Water Fish breeding, but that is another discussion). Its use proved uneventful.
It seems most people fail due to the inability of the plantlet to get established and grow. I discovered, as brought up in Keith Davis's excellent article on the growth of his Dendrophylax lindenii 'Glade Spirit' FCC/AOS, "A Ghostly Pursuit" (Orchids Vol. 78 NO.7 July 2009), that the choice of a suitable substrate is key, as well as high light levels . A couple of years ago I had the good fortune that my neighbor's Bradford Pear (Pyrus calleryana) split and fell during a storm. I peeled off several nice large furrowed pieced of bark.
Mounting a small plant of Dendrophylax lindenii
I drew on my experience from other obsessions, Bonsai and stony coral aquaculture (I know where I find the time). I realized adherence to the substrate was key, and where the majority of failures seemed to occur. Simple tying was not always reliable. I had a bright idea. Cyanoacrylate glue, actually an acrylic resin ( i.e. Krazy Glueâ„¢, Super Glueâ„¢), long used in the propagation of stony corals for adherence to substrates and now even in some medical procedures, seemed like a good option.
I took my languishing remaining plant and glued it to a nice piece of deeply furrowed bark I had salvaged. This is where the Bonsai comes in. Rapeseed cakes, an organic fertilizer made from the seed of Brassica napus has been used for centuries in China and Japan as an organic fertilizer. The seeds, processed and sun-dried, are molded to small pellets. They are available from any good bonsai supply source (5-2-1, or 5-4-1 if bone meal has been added). We place them on the soil of the Bonsai in the summer to allow a constant slow organic fertilizer source. They are generally replaced every 50-100 days. I glued a few of these to the top of the mount so the water would run over them; I tucked a few of them into the roots, as the plant grew larger. Easily hidden by the Spanish moss draped over the plant, I found spectacular results.
I moved my plant to the apex of my greenhouse near the Vandas being that it was a member of the Tribe Vandeae. I took an old compact fluorescent light fixture, from my now abandoned coral hobby, and mounted the (2) 21" 55W dual spectrum compact fluorescent reef lamps (True Actinic & 10000°K Super Daylight) at the top of the greenhouse, mostly so I could see in the dark months. While the bulbs are supposedly much too old to be of benefit to plants any longer (it is recommended they be replaced yearly), I run them 16 hours a day in summer and 14 hours a day in winter. I hung the Ghost a few inches under this for supplemental light. I did set up a thermal cut off so if the temperature goes above 90 ºF, the lights turn off. These simple devices are available inexpensively at most pet supply stores for control of temperature for reptiles.
Last year I was thrilled to see a spike emerging in May. It bloomed with a single beautiful flower. I was overjoyed.
Over the past year, the growth has almost doubled with the roots reaching 30" tip to tip vertically and about 8" across. The Spanish moss is thriving as well. As mentioned, in late March this year, seven spikes emerged. They opened in mid-May. I took it to my local IOS meeting and caused quite a stir. Maybe someday I will have it judged.
Since I maintain optimal growing conditions year round to maximize growth, I do not utilize the dry and cold (45 º F) dormancy some growers have successfully used to flower. Here is what I refer to as the "Hale Method" to those who ask:
What the finished mounted plant of Dendrophylax lindenii looks like.
- Plants must have firm adherence to a suitable bark mount with a good quality cyanoacrylate glue. I recommend the gel version.
- Minimum humidity of 65%. Don't worry if this dips in mid-day when the temperature sometimes approaches the high 90's. Alternating moist and dry conditions are key and normal in its natural environment. I do not move the plant around once established in a greenhouse location.
- Rapeseed cakes glued or wired to the mount.
- Year round full strength fertilizer weekly. I use 1 tsp. gal. of 7-9-5, 3-12-6, or 15-5-5 depending on the season, using Chicago tap water. I find my average water pH is 7.6, and general hardness (GH) is 120-150 ppm. This is considered moderately hard, but I find I still get excellent results. Again, I do this year round with no dormancy.
- Winter minimum daytime temperature of 75º F. With sun, this often rises to the 80's. Nighttime minimum of 60º F.
- Summer venting at 90º F with 35% shade cloth applied March-October (for my latitude). Small circulating fan helps equalize temperature and humidity preventing "hot-spots."
- A bright sunny spot in your greenhouse, as Keith Davis has mentioned, i.e., where Cattleya will grow.
- Live Spanish moss, though no one seems quite sure why this helps, is also an excellent "indicator" plant of your culture conditions. If your moss does not flourish, your plants will not either. I leave it on year round.
- Anecdotally, supplemental lighting has seemed to help me. This may be due to the short day length during the winter in Chicago. I also do not grow any orchids dependent on day length for flowering, which may be of concern to some.
Acknowledgements
I want to recognize the AOS for their education and conservation efforts, and encourage all enthusiasts to speak about your passion to our young people. You never know whom you may inspire! I also wanted to thank Herman, Greg and Liese at Oak Hill for making this plant available to us.
Reference
Keith Davis. "A Ghostly Pursuit". Orchids. 78, No. 7 (July 2009): p408
Author Jeff Hale with his beautifully-bloomed plant of Dendrophylax lindenii