Some Common Questions and Answers !


It occurred to me that many visitors to this site could benefit from the questions that others have asked. So from now on, I will endeavour to post the questions and their corresponding answers here. Hopefully, some of you will find this information useful !

Just click on the question below to go to the corresponding answer :

  1. Q: Is Eria coronaria a valid species ? If so, what are its cultural requirements ?
  2. Q: What are the differences between Dendrochilums arachnites and wenzelii ?
  3. Q: What kind of files are the pictures I see on the web ? How can I save these files to my hard drive, every time I try to save one I end up with an "htm" file, but no picture ?
  4. Q: What does the term "multifloral slipper orchid" mean, and what are some examples ?
  5. Q: Can you tell me about Aeranthes arachnites ?
  6. Q: Can I grow a real Vanilla Orchid in my home ?
  7. Q: I have a terrible problem with crown rot in my orchid collection, any suggestions ?
  8. Q: Can you tell me about Chinese cymbidiums ? Are they suitable for indoor culture ?
  9. Q: What is the difference between P. rothschildianum seedlings ? I have seen them priced from $30 to $250 for the same size and would like to know why the price difference between them.
  10. Q: What does the term "colchicine treated" mean ?
  11. Q: What does Den. Green Lantern look like and is it hard to grow ?
  12. Q: How should I grow a Promenea xanthina?


Q: Is Eria coronaria a valid species ? If so, what are its cultural requirements ?
A: Yes, E. coronaria is a valid species. I've been growing one for several years now, and it is definitely worth growing. Mine was collected in Thailand, but this species does have a fairly wide distribution spanning the Himalayas, Burma, Thailand and Malaysia. Of the Erias this species tends to prefer somewhat cooler and shadier conditions, but mine still does fine with very hot summers, as long as it is kept moist at all times ! Erias are closely allied to Dendrobiums, but are usually placed in their own subtribe called Eriinae, and on the larger scope they end up in the tribe Epidendreae. If you have the space, try a few of the other species. I'm on the lookout for some more myself, since it is an unusual and very diverse group (not unlike orchidists themselves ! ;)
Q: What are the differences between Dendrochilums arachnites and wenzelii ?
A: It has been my experience that arachnites is yellow and wenzelii is various shades of brick red. The flower of wenzelii is smaller and more "bristly" than arachnites which has wider petals and a flatter flower. If you do have a "red" form of arachnites, then the form should be similar to that of the "standard" form. I too wish that there were more information on Dendrochilums as they are becoming more popular and quite a few species are emerging, each more intriguing than the previous.
Q: What kind of files are the pictures I see on the web ? How can I save these files to my hard drive, every time I try to save one I end up with an "htm" file, but no picture ?
A: The pictures that are on the web are either *.gif files or *.jpg files. The *.htm files which you downloaded are the files which organize the text you see in web pages, and they indicate the location and names of the pictures that they contain. If you are using a browser like NetScape 3.0, click on a picture with the right mouse button and this will give you the opportunity to save that picture file. If your browser does not support this, then view the "Document Source" and this will tell you which picture files are being used and then you can access those directly and save them under your "File" options. (If you are not a computer geek, like myself, certainly the first option is more straightforward). Larger pictures tend to be .jpg files because they take less space. To convert either of these formats to a .bmp file you can use most any graphics program like iPhoto Plus, FotoTouch Color or Paint Shop Pro... Most graphics packages on the market will allow you to import these file formats and then save them as a .bmp file. I hope this helps !
Q: What does the term "multifloral slipper orchid" mean, and what are some examples ?
A: True multiflorals fall into 2 categories :
1) Sequential multiflorals that can have many flowers, but usually only one open at a time. The older flower will usually hang on a couple of days as the next flower opens and then the old one drops off, this keeps the plant in bloom for quite a long period.
2) Simultaneous multiflorals that can usually have up to 5 flowers, nearly all of them open at the same time... a new one opens every few days.
Some examples are :
Prince Edward of York - Simult. multifloral, 4 or 5 flowers
Lynleigh Koopowitz - at very most 3 flowers, usually 1 or 2
Harold Koopowitz - at very most 4 flowers, usually 2 or 3
Keelingii - somewhat simult. multifloral, up to 4 or 5 flowers
Magic Lantern - at very most 2 flowers
Armeni White - at very most 2 flowers
Andronicus - somewhat simult. multifloral, Up to 4 or 5 flowers
Peg Samuel - 2 or 3 flowers
delenatii - at most 2 flowers
Delrosi - somewhat simultaneous, up to 3 flowers
(henryanum x spicerianum) - up to 2 flowers, usually 1
hookerae - usually 1 flower
kolopakingii - most floriferous paph, usually up to 9 flowers, potentially more
(kolopakingii x sanderianum) - should be up to 6 or more flowers, somewhat simultaneous
Roger Sander - up to 4 flowers, usually 3 somewhat simultaneous
Jogjae - somewhat simult., up to 5 flowers usually 4 flowers
Frank Booth - up to 6 flowers, usually 5, simultaneous multifloral
Oberhausen's Diament - up to 5 flowers, usually 4, somewhat simultaneous
Michael Koopowitz - simultaneous, up to 5 flowers
Sander's Pride - simultaneous, up to 4 flowers
Mount Toro - simultaneous, up to 4 flowers
Phrag. April Fool - On a mature plant, multifloral over an extended period.
Where I have used the term "somewhat simultaneous multifloral", it is usually a cross between a sequential and a simultaneous multifloral. This normally adds a couple of days more than simultaneous types between consecutive flowers opening.
Q: Can you tell me about Aeranthes arachnites ?
A: This species is endemic to Reunion Island. I don't have this particular species, but understand that it is very similar to grandiflora, but with a smaller flower. The other species of Aeranthes that I do have, do quite well in subdued light, suitable for paphs or phals. I have also had success under 4' fluorescents. The key to keeping them healthy is to not let the temperature get too cool. Any less than 13 C. seems to be a problem, ESPECIALLY if moisture is high... then they spot and go yellow quite easily. When the temperature is warm, and they are potted in a light, airy mixture they respond well to lots of moisture. The inflorescences are long-lived, so don't cut them off until they die back. The light green flowers are quite attractive, and a nice addition to any collection.
Q: Can I grow a real Vanilla Orchid in my home ?
A: To my knowledge there are only a few of the 100 or so Vanilla species that are used for commercial vanilla production, the primary species is Vanilla planifolia. There is also a variegated form of the species, but I have never seen it. It is possible that the vanilla beans (seed pods) of other species are edible, but I am not aware of which others might be used. We regularly offer this species for sale. Because of its beautiful lush foliage and vining habit, it looks more like a "houseplant" than most orchids do. It prefers moderate to bright light, intermediate to warm temperatures and good humidity. It is usually capable of blooming at about 6 or more feet in length, and produces very fragrant, cattleya-like blooms that last 1 to 2 days each.
Q: I have a terrible problem with crown rot in my orchid collection, any suggestions ?
A: I hope that I can offer some food for thought, if not the direct cause of your dilemma. I believe everyone, at some time, has had problems with crown rot. Some paphs are particularly susceptible since many have very tight crowns, making for the perfect environment for crown rot. Anyone who claims to have never encountered crown rot is simply not being honest, and wants to portray a savvy that is not merited !
There are many possible causes for crown rot to occur :
1) water : I have found that tap water can lead to crown rot because of the salts which accumulate in the crown. You may be using a towel to soak up excess water, but if you're using tap-water exclusively, then there will always be some which manages to find its way deep into the crown where you can't reach it.
2) fertilizer and other chemicals : Much like tap-water, these substances can accumulate in the crown, just beyond reach. As their concentrations increase, their toxicity increases and will kill the crown, which then leads to rot.
3) temperature : Cool temperatures and water will kill the crown and lead to crown rot. It sounds like your temperature range is okay, but be sure to water only in the morning so that there is plenty of time for the plants to dry off.
4) water temperature : If the water used is too cool, it can have the same effect as growing under too cool conditions, regardless of what the room temperature is.
5) inadequate drainage : If the humidity is very high, especially in smaller enclosed spaces, moisture around the roots in addition to some in the crown will lead to crown rot. Contrary to most beliefs, paphs do like to approach dryness between waterings. I tend to use a coarse mix, particularly for larger plants. I always underpot as well. This provides a fast-draining and quick-drying potting mix. I find that under these conditions, even moisture in the crown will not be a problem as the plant actually seems to absorb it from there if the roots are somewhat dry.
6) inadequate light : If the plants are grown too shady, then this coupled with moisture can lead to crown rot.
7) slow growth : Many of the plants which succumb seem to be the slower growers. This could be that all the factors I have listed will weaken the crown, and lead to its eventual demise. The key is to keep all conditions optimal for growth, hence you will always keep new leaves coming out of the crown and crown rot will diminish markedly.
8) air movement : This is probably the most important factor. All too often, the need for air movement is underestimated. Air movement from several sources can greatly improve plant growth and performance. An overhead fan is good, but perhaps an oscillating fan at plant height, might make all the difference. I do not think it is possible to have TOO much air movement for orchids. When you come to see my setup, you'll see what I mean ! If this is not feasible, then perhaps just some supplementary air movement on the days that you water. There is nothing wrong with having a fan blowing directly on your plants, or across the tops of the leaves. This will dry them off faster, and promote healthier growth.
Q: Can you tell me about Chinese cymbidiums ? Are they suitable for indoor culture ?
A: I have quite a number of the smaller chinese cymbidiums. As a rule, the chinese cymbids are always smaller than most of the hybrids you see around, and as an extra bonus many of them are pleasantly fragrant. But the plain form of the species Cym. sinense, can grow to be a fairly tall plant if it is growing well. If you want something more compact, I would recommend most of the Cym. ensifolium varieties, or one of the more exotic varieties of sinense, as they stay quite small and will grow quite readily on the window sill or under lights. I usually describe their requirements as being similar to phalaenopsis. There are a few other small species, but they start to get more expensive as they are much harder to come across.
Q: What is the difference between P. rothschildianum seedlings ? I have seen them priced from $30 to $250 for the same size and would like to know why the price difference between them.
A: Your question about the roths is a tough one. Personally, I find it hard to comprehend why any roth seedling would be as high as $250. However, my experience has taught me that some people think they can get away with charging exhorbitant prices, when those prices aren't justified. As far as the lower price range, notice if named clones have been used for the parents of the seedling. Ideally, you want to know that the breeder did not indiscriminately put a seed pod on a substandard plant that was blooming. Particularly with roth, there has been much breeding and selection in the species in captivity. So, if you want to get a better chance of having a really nice flower for all your investment of time and money, you should look for a seedling that has at least one awarded parent. If yours is the result of two AM (the second highest award) clones being crossed together, so the odds of the flower being above average are very good. I hope that this sheds some light on the mystery of where the prices come from.
Q: What does the term "colchicine treated" mean ?
A: Colchicine is a mitotic poison that is usually used when seeds are germinating to increase the DNA count. The aim is to produce tetraploids, which have double the usual number of chromosomes. The end result is that the flowers tend to be brighter coloured and larger than normal. The flip side of this, is that these plants tend to grow slower than their normal counterparts, so flowering can often take 6 months to a year longer than usual. When the seeds are treated with colchicine, the conversion to tetraploid is usually about 60%, so there is no guarantee that each seedling will have its gene count altered. Also, there is no guarantee that the optimal amount of colchicine was used for the correct period of time. If too much colchicine is used, or the seeds are left too long in the solution, then you can get hexaploids (3 times the usual chromosome count), octaploids (4 times the usual), and so on. These plants are usually severely crippled and rarely live very long.
Q: What does Den. Green Lantern look like and is it hard to grow ?
A: My Green Lanterns are all currently in bud or bloom. I find that the plants of this group (the Nigrohirsute - black haired types) do well for me under moist, bright light conditions with lots of air movement. They are quite easy to grow, and flower very readily provided that they are happy. The flowers also tend to last quite a while, often 4 months or more. Be careful not to overpot them, and they are not heavy feeders. I live in Ontario, Canada, so if you live elsewhere, optimal conditions may differ. Good luck, this is a very rewarding group of dendrobiums.
Q: How should I grow a Promenea xanthina? By all accounts, it should be an easy one to grow and flower. Right now, I'm growing it warm and shady (about 1500fc). I've had this plant for 3 years now and it just won't bloom. Should I give it a winter dry rest til the leaves fall off completely? Last year I did give a (semi) dry rest but that didn't help. Any advice will be much appreciated.
A: In my experience, if you dry it out completely, you will probably kill it ! I have found xanthina is one of the harder to bloom of my Promenea species. I did however, get several to bloom this year, even on very small plants, by keeping them moist in a well-drained mix, and giving a generous diurnal dip (80 F days, 57 F nights). After a couple of months, suddenly I had buds coming out everywhere. My plants seem to like shady, warm, moist conditions for most of the year otherwise.

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