Dendrobium culture: A shade house for Dendrobium anosmum

Dendrobium anosmum needs exposure to full sunlight to bloom well.   But too much sun burns the plants.   I build this wooden shade house so that I could grow my plants in a place where they got the right balance of sun/shade.   The shade house was oriented so its longest axis was perpendicular to the sunrise in the spring/autumn equinox.   It was eight feet tall so that the long canes of the Dendrobiums could hang down without touching the ground.  It was 10 feet long and four feet wide.  To shield the orchids from the harsh midday sunlight a camo fabric was used.   In places I also used black shade fabric.  Notice the camo fabric has a multitude of holes.  This made a pattern of sunlight and shadow that moved across the plants during the hottest parts of the day.   The desired effect was to achieve something similar to the way sunlight is naturally filtered by the leaves in the forest.

 But the key thing of the shade house was its open sides.  To the east of the shade house there were few trees, so the Dendrobium and other plants would get full strength sunlight from about 8 am to 11 am.   The west side of the shade house faced the closed canopy of the forest, so after midday, the plants were in the shade.   This mimics what happens in the natural habitat, where a plant that is growing in the side of a tree can get plenty of sunlight during part of the day and its on the shade after that.

 I used to have many of plants of Den anosmum.  So many plants that when the shade house was full, I could grow plants that needed lower light levels under the Dendrobium.    I hung the Den anosmum in the east side of the shade house and in the center of the structure, these were the areas that received the most intense sunlight for the longest time.   Under the Dendrobium, in the ground I grew Phaius, Calanthe, Phaiocalanthe, Cymbidium, Paphiopedilum, Vanda and Angraecum.   The shade was narrow to maximize the plants exposure to light while protecting them from the midday sun. 

 During the rainy season, in the afternoon the sky would get cloudy and it would rain, this would reduce the intensity of light in the afternoon.    But in the dry season there would be very sunny days, uninterrupted by any clouds, and this threatened the plants with sunburn, even those that were in their resting phase.  To avoid this, I would put a few old dry palm fronds on the roof of the shade house.  This reduced the level of light to tolerable levels.

When the Dendrobium were ready to bloom, they were moved to the terrace.  You can see the result in the photo below.

The wooden shade house was destroyed by a tropical storm.  It was rebuilt, much stronger, now made of two inch metal pipes.  This one lasted until Hurricane Maria dropped the top of a Teak tree on it.

Myrmecophila culture: Why my plant won't bloom? A checklist of possible causes

The most common question I get asked about Myrmecophila orchids is “why won’t my plant bloom?” I have decided to make a checklist of the reasons Myrmecophila might not bloom. This will help guide you to find the way to make your plants bloom. 

1. Is the plant adult sized? Myrmecophilas are plants that in the wild live in a symbiotic relationship with ants that live inside their hollow pseudobulbs. These ants fertilize the plant with their feces. Plants in cultivation that don’t have ant colonies might become stunted and never reach adult size. So the first thing is to get an ID the plant and check on the size of an adult pseudobulb. If the pseudobulbs are smaller than the reported size for the species they you need to make sure you fertilize this plant with a high nitrogen fertilizer and give it plenty of water when it is producing new pseudobulbs. 

 

2. Is it getting enough sunlight? Myrmecophilas are not plants that bloom in shady spots. They will grow well, and might eventually produce a large clump of pseudobulbs. But they will not bloom. If a plant is an adult and is not blooming, the next thing to check it if it is getting the level of light it needs. I have seen Myrmecophilas growing quite well in places where they get full sun for most of the day. Personally, I put my plants close to the shade cloth, I grow them under a shade cloth that allows most of sunlight to come through. The best plants I have seen were grown with full exposure morning or afternoon sun, but protected from the midday sun by shade cloth or the canopy of a tree. 

 3. Is it in the proper location for blooming? Myrmecophilas are often planted on trees with dense canopies. This keeps the plants in shade. They will grow well but not bloom. A friend had a massive plant of Myr humboltii growing in a citrus tree. It had never produced a single flower. A hurricane severely damaged the canopy of the tree, allowing full sunlight to reach the Myrmecophila. As a result, the plant bloomed. 

 4. Is it receiving the care it needs at the critical time in its growth cycle? Most people I know affix their Myrmecophilas to a tree and that is that. No watering, except for rain, or fertilizing, except what it gets naturally from the tree or from ants if they have colonized the plant. This is a hit or miss approach. Some plants will grow well and bloom, other will rarely bloom and some will never bloom. I have seen Myr humboltii and Myr exaltata growing on the stems of palm trees doing well and blooming. I have seen a massive plant of Myr humboltii under the thick canopy of an avocado tree, with no evidence of it ever blooming. You need to observe your plant, and when it is producing a new pseudobulb, give it the watering and fertilizing it needs. 

 5. Is it healthy? Some Myrmecophilas are attacked by a type of fungus that kills their stems and primordial buds. You can tell this because part of the stem that should be green look like cork. The sad thing about this is that often nothing can be done. The warning sign is often that the plant is not producing new growths. The fact that the rest of the plant can look good even if it has lost all its capacity to produce new growths, and can remain looking good for years, is a confounding thing. Plants like this will not bloom ever. On occasion an older side bud will produce healthy new growth. But if a plant has not produced new growths after a few years, it is probably a lost cause. 

 6. Is the plant getting the proper nutrition? Sometimes you can do all the above things and still a plant won’t bloom. Sometimes a few extra things can give it the push it needs to bloom. I have used a dilution of Epson salt to give the plants more access to magnesium, in particular those that are growing in full sun and look yellow. A fertilizer with a high nitrogen concentration is recommended when the plant is producing new growths.

A small pendent Dendrobium hybrid, Dendrobium Adastra x Den. parishii

Dendrobium Adastra x parishii

Dendrobium Adastra x parishii

Dendrobium Adastra x parishii

Dendrobium Adastra

Dendrobium anosmum

Dendrobium cucullatum

Dendrobium parishii

I brought this small Dendrobium hybrid at a huge Spring orchid show in 2009 that was held at Plaza Las Americas, the largest Mall in the Caribbean.  One interesting feature of these shows is that every year a few new and interesting plants are brought in, sold in quantity, and then never seen again for sale.   Because this has happened a number of times I am always on the lookout for orchids that I know are rarely exported.  This little Dendrobium is one of those rare and exciting finds.

This little plant combines the genome of three of the most outstanding species of Dendrobium of the section Dendrobium.  This orchid is the result of the cross of Den. Adastra (anosmum x cucullatum) and Den. parishii.   It is interesting to note the flower of this hybrid doesn’t resemble too closely any of the parents and has a unique charm all of its own.  One surprising characteristic of this plant is its small size.  The canes of my plant are between 12 and 15 inches long, pretty small considering than a local anosmum can easily produce five foot canes and I have some clones of cucullatum reach more than six feet long with ease.  It appears that the influence of the parishii parent has resulted in a reduced cane length in this hybrid.  But I must confess the size of this plant might have also been influenced by the way I culture it. 

One vexing problem I have had with parishii derived hybrids is their vulnerability to cane rot under my local conditions, something that also plagues my parishii plants.  However not all my parishii hybrids are equally affected, those that are in baskets with excellent drainage fare the best, those in pots fare poorly.  Because I didn’t want to lose this plant to rot I put it in a tiny basket with just enough moss to give the roots something to hold but not enough that it would stay sopping wet for hours.  As a result the root ball of this plant is comparatively puny for its size.  But since after three years under my care it has now shown itself to be quite hardy I plan to move it to a larger basket where it will be able to develop a larger root ball.  Unfortunately it has shown no inclination to produce two canes at the same time as anosmum sometimes does and its quite stingy producing keikis having produced just two so puny that I will wait until they have two canes to remove them.

As far as culture goes I grow them like I grow my anosmum except that this one is kept in a shadier location until I have more plants and can test them for resistance to several hours of full sun exposure.  Indications on growing anosmum are located elsewhere in this blog, a link can be found at the bottom of this blog page.   Compared with Adastra, anosmum and cucullatum this orchid is a relatively slow grower.  The canes sometime have slight sidewise twists, an odd feature that none of the parental species show under my care.

The flowers of this hybrid have a better shape and presentation than the flowers of any of its parents and the pink color is outstanding.  But sadly they are not scented and they are produced in limited numbers.  The relative small flower count might be due the way I grow it so the flower number will probably increase significantly if I expose it to more sun but that will be tested in the future.   Personally I would love to see a flower with the shape and color of this one but with a size comparable to the flowers of anosmum which can be four inches wide.  I sometimes wonder what would come out if someone would cross this plant with Dendrobium primulinum var. giganteum which has an enormous lip with a spectacular orange coloring in the center.  Alas it is a fantasy at this moment but, you can always dream!

Vanda merrillii Ames & Quisumb. 1932, a collector's item for those that value Vanda species

A freshly opened flower of var. inmaculata

A fully maure flower

Top view to show the degree of reflection of the petals

Variety rotorii

Variety rotorii

Vanda merrillii is native of the phillipine island of Luzon where it grows at altitudes of 1,500 feet.  This orchid has been a long time member of my orchid collection and has shown itself to be a hardy survivor of both overwatering and neglect.  My plant has grown at its best when cultivated in an area where there is high humidity and when it has been fertilized every week with a weak solution of fertilizer.  My problem has been that I usually don’t fertilize plants that are not growing and sometimes forget to fertilize this Vanda too.  That has resulted in slow growth, leaf loss and sparse flowering.  So my recommendation on this plant is to water it generously and to keep a conscientious schedule of fertilizing it.  This orchid seems to prefer a slightly shadier light regime than my other plants of this genus, I give it only a few hours of sun in the morning and light shade the rest of the day.

The flowers are produced in the spring and are long lasting. They are highly colored but unfortunately the petals twist back shortly after the flower opens giving it the appearance of a diver doing the swan dive.  Different clones differ in the amount of twisting, some only twist the petals back slightly others twist them back so much they end up almost parallel.  There are several color forms of this species that vary in the amount of red or yellow in the flower and even some that have a very dark color.  In Puerto Rico I have seen plants of the variety rotorii and some that might have been var. inmaculata but that were not labeled as such.  Plants of var. rotorii are noted by their rich red color that covers almost all the flower.  Plants of the var. inmaculata show extensive yellow areas in the basal portions of the sepals and petals with the areas of solid red color confined to the margins of the floral segments.  I think this plant will grow well in most areas of Puerto Rico, however to get a good flower show out of this Vanda you need to make sure it get the watering and fertilizing regime that it prefers.  This plant is rarely seen in local orchid collections.  I regard it like a collector’s item for those growers that appreciate the particular charms of the various Vanda species over the generally huge size and roundness of the most commonly available hybrids.

Dendrobium farmeri, a small Dendrobium that can produce an impressive show

The white form of the species, albiflorum

The most common form in the wild

A very light pastel pink form

A highly colored type with smaller slightly cupped flowers

A pink form, the orange lip is due to the fact that they were photographed with flash

Two slightly different forms side by side, note the long slits for aireation on the pots

The albiflorum form next to a pink one

A plant almost totally covered with flowers

This deeply colored form even has a purple dot in the lip

Dendrobium farmeri is an orchid that has a geographical distribution that goes from the eastern Himalayas to Malaysia.  This means that plants of this species can grow in environmental conditions that range from fairly cool to sweltering hot.  But this doesn’t mean that all plants of this species will grow under any condition that you can expose them.   There are local populations of this species that have adapted to certain regimes and will not bloom in the environmental conditions don’t match their seasonal needs.  Visitors to their natural habitat remark that the plants are often seen growing in trees near river courses.  I have had the experience of growing several different plants of Den, farmer, I will detail my experiences in the following paragraphs.

A few years ago a friend gave me as a gift a very peculiar farmeri plant.  It had a long and thin stem that about halfway of the way up the stem would fatten to a ridiculously disproportionate girth.  It was the tallest farmeri that I ever seen with canes 30cm long.  My friend gave me the plant because it would not bloom for him (he lives in the coastal lowlands of Puerto Rico), at that time the canes were about 15 cm tall.  What made them grow to 30 cm was the heavy application of water and fertilizer during its active growth phase.  After two years under my cultural regime the plant produced the two largest inflorescences that I have ever seeing in a farmeri plant.  I have wondered this plant was palpebrae but it lip didn’t show the fringe that palpebrae flowers are said to have.  This plant sadly died unexpectedly of a stem rot that had never previously attacked any farmeri plant in my collection and has never attacked one since this one died.  This plant was cultivated in a plastic basket that it eventually filled with roots, the only potting material were several large pieces of bark.  The flowers of this orchid were pure white with a bright yellow coloration in the lip.   This orchid was a large sized representative of the albiflorum variety.  All my other plants are smaller than this one and don’t show the shape of the stem this plant had.  I suspect this plant came from and mountainous region and needed a sharp drop in temperature to stimulate blooming.

I have several smaller (less that 20 cm tall) slender types will bloom equally well in the mountains as in the coasts of Puerto Rico.  In the early nineties there was a huge importation of Den. farmeri, the plants were sold at the Puerto Rico Orchid society show in San Juan.  When these plants bloomed they all turned out to be the white variant of the species Den. farmeri albiflorum.  For many years var. albiflorum was the only one that was seen in orchid exhibits in the island.  During the course of the nineties I saw exhibited some impressive specimens and I personally had a plant that would produce more than a dozen inflorescences at the same time.  Unfortunately many plants of this importation showed cupped, nodding flowers, this detracted from the beauty of the blooms.  It is not clear whether this cupping of the flowers is due to genetic or cultural causes.   

A few years ago there was another importation, this one consisted almost entirely of the pink form of the species.  I saw one plant in bloom and was so smitten with it that spent $60 dollars. That is right I spent almost five times the value of a seedling of this type of orchid in a single plant.   But I loved the purplish color of the flowers and was quite happy with my purchase.  In due time the flowers fell (the flowers of this plant last from a week to ten days, less time if weather is really hot).  In about two week the plant bloomed again and to my surprise the flowers were different!   In this blooming the flowers were pink, larger and fuller than in the firsts bloom.  A few weeks later the plant produced a single inflorescence which was again different from the previous two.   In this case the flowers had a very delicate pastel pink color.   After careful examination of the plant I had to conclude that I actually had three plants growing very close together in a single pot.

With extreme care I disentangled the three different clones and potted them separately.  Two of them have been growing well with no problems, the third one almost died.  Why?  Because under my conditions farmeri seems to be extremely vulnerable to rot after it has been repotted.  The plants can live for a long time, a decade or more filling and growing over their old pot in great health.  But every time I have divided and repotted the plants I have lost many of the pieces.

My saddest experience was when I took out of its pot a specimen plant of the variety albiflorum that had been in the same basket of about ten years.  I took the plant out of the basket divided it in several pieces and potted each piece separately.  After a few days they started dying, at the end only a tiny two cane piece survived.  This piece has been growing painfully slowly but at least is alive and has started producing small but pleasing inflorescences.  So what is my advice on potting this plant?  Put it into a basket that will allow the plant to grow for years without the need to repot.  Use the hardest most decay resistant media you can find, don’t use cheap bark and for Peter’s sake don’t even consider the super cheap landscaping bark for this orchid. 

The most vexing problem I have had to deal with this species is the proclivity of some clones to produce new canes lower in the stem than the original cane.  As a result of this habit the new canes end up growing through the media and sometimes into the media before growing upwards.  These types may be better grown in slat baskets or mounted on tree fern slabs.

For most of the year I don’t fertilize this orchid, I only fertilize when the plant is producing new growths.  When this plant is growing the canes grow comparatively fast so you need to give it fertilizer frequently.  When my plants I growing I give them diluted fertilizer at every watering.  I use whatever fertilizer I have on had, be it 20-20-20 or any other combination, I have never seen any difference in growth as long as I fertilize the plant regularly.

My plants bloom in February, March and April.  The albiflorum type produces a single flush of inflorescences that open all at the same time.  The pink flowered types bloom once a year when they have few canes, but once they grow large they bloom twice, once in February and again in March or April.  My main problem has been that the flowers are wildly attractive to thrips which will attack them in great numbers even when they have been rendered toxic by the application of pesticides.  To avoid having the flowers damaged with these hateful pesky pests I move the plants indoor for the duration of the blooming period.  As the plants mature and gain size they can produce very impressive flowerings.

These plants need bright light to bloom well.  I grow my plants in a terrace where they get full morning sun for two to three hours and then sunlight filtered through the trees the rest of the day.  Too much shade results in poor blooming or even no blooming at all.

When my plants are growing I water them almost daily to sustain the rapid growth of the canes.  During the summer my plants get a daily soaking from the thunderstorms that form over the mountains every day.  The plants take the wetness with little complaint.  When the dry season starts in December I stop watering the plants and allow them to dry, but not so much the canes shrivel and twist, if the canes start to get too wrinkled I water the plant lightly.

This plant is an excellent addition for an orchid collection if you can fulfill its relatively modest needs.

Vandachnis Premier, a large growing orchid that will delight and impress visitors

Vandachnis Coronation is a hybrid of Arachnis  flos aeris and Vandopsis lissochiloides

When the sun backlights the flowers they show a beautiful yellow color

A single inflorescence, the inflorescences can grow to five feet of lenght

Five plants were grown side by side so that their inflorescences would bloom together

The aim is to delight the viewer with a massed display of flowers

Most orchidists I know grow their orchids in pots and baskets so that they can be easily moved for display,for cultural reasons or to protect them from the weather. But there are some plants that become too large to grow this way. These plants are generally displayed in the growing area since moving them is not an option. As a result many large growing monopodial orchids are usually grown in the midst of a plethora of other orchids in pots, baskets, stands and along with other garden brick-brack this often means that their flowers are not displayed to their best advantage. Given that even one of these plants can take a big chunk of real state when grown to full size, it is understandable why few people have groupings of them. My plants of Vandachnis Coronation have large and showy inflorescences and I decided to grow together a few of them so that when the plants bloomed there would be a mass of flowers to delight and impress the visitors to my garden.

But even though this plan sounds as a fairly easy proposition growing a group of Vandachnis takes some planning given their large size and slow rate of growth. First you need a place where you can grow the plants undisturbed for at least three years. This length of time is dictated by the fact that although by its Vandopsis parent standards of growth these plants grow lightning fast by the Arachnis parent standard their growth rate is glacially slow. Also you need an area where there is good support for the stems of these plants. Vandachnis Premier can bloom well when it is six feet tall, but they bloom even better when they reach seven or more feet. The inflorescence of a small plant can be a single unbranched modest affair, the inflorescence of a tall and strong plant can have four branches and be five feet long.

I placed five plants fairly close together side by side in 2006 and started caring for them and waiting. In 2008 I got the grouping of inflorescences that I wanted. As you can see in the photos there were dozens of flowers massed together. The flowers of Vandachnis are relatively thick and leathery and an inflorescence can spend weeks opening new flowers. This means that the display lasted for about three months before all the flowers had fallen. But the blooming was at its best for about a month, just after most of its flowers had opened by before the first ones to open had started to drop.

Unfortunately the plants were damaged by the winds of a storm which meant that the blooming 2008 is still their best show. However I am planning to put a new group together and see if I can get even more inflorescences and flowers all at the same time.
For cultural advice on this plant go to: http://ricardogupi.blogspot.com/2008/10/arachnis-culture.html

Calanthe rubens and Cal. Grouville two terrestrial orchids that are relatively easy to culture

Calanthe Grouville a hybrid

Calanthe inflorescences cascading from my terrace

Here you can see the way the flowers of Calanthe Grouville change color in my garden

A large plant of Calanthe Grouville with inflorescence

Calanthe Grouville plant with inflorescences that have been blooming for months

Plants ready for repotting, you can see the new buds at the base of the pseudobulb, for more details see text

This pesudobulb has two developing buds

Calanthe rubens

A mass of Cal. rubens inflorescences

Here you can see the shape of the Cal. rubens pseudobulbs

From what I have read about the start of the orchid hobby in England in the nineteen century, it seems the genus Calanthe was widely grown and much admired. In fact the first orchid hybrid to bloom, although not the first one ever made, was Calanthe Dominyi (Cal. masuca x Cal. furcata). Nowadays Calanthe has become rare in the orchid market although it still possible to find hybrids and species if one searches for them hard enough. But in Puerto Rico Calanthe has never been a popular genus and most orchidists are unfamiliar with even the most common species. I will detail my own experiences with this genus and why I think it is not favored among local growers.



The genus Calanthe has two group of species, the evergreen and the deciduous ones. General guidelines for the culture of both groups are similar in some respects but their biology also makes up for some major and striking differences. I have never grown evergreen Calanthe and I have never seen them shown in local orchid shows so I cannot comment about them. Those evergreen species I know from the literature hail from temperate climates and probably would die if kept at the tropical temperatures of the island of Puerto Rico.


My experience growing Calanthe has been with a deciduous tropical species and a hybrid of the same type. The species is Cal. rubens, the hybrid is Cal. Grouville. Calanthe rubens produces small pink flowers over a period of a few weeks in an erect inflorescence. Calanthe Grouville produces flowers that are somewhat larger than those of the preceding species and that are white and red. I my locality, and I don’t know if this is true elsewhere, the flowers of Calanthe Grouville start turning pink as they age. The flowers of Cal. Grouville open over a period of months on a single inflorescence that arises from the base of the pseudobulb.


Let’s start with the species, Cal. rubens. I suspect that the seasonal growing and resting cycle of this species is probably the source of confusion and frustration to orchid growers whose whole experience growing orchids is circumscribed to growing ephyphitic orchids such as Cattleya, Dendrobium and Phalaenopsis. The reason for the confusion is that for part of the yearly cycle of this species the plant discards both its leaves and the root system. The pleated leaves that looked so elegant earlier in the year start to deteriorate as soon as the inflorescence becomes close to blooming and become yellow and fall just as the first flower is opening. This seems to be a source of distress for those orchids growers unfamiliar with this plant and some assume the plant is sick and is going to die. The fact that the leaves of Calanthe tend to look awful and the end of the growing cycle, even before they are shed is also something that doesn’t endear it to growers that prefer clean and immaculate leaves on their plants.


Cal. rubens blooms at the start of the year in my garden, plants bloom between January and February. In this stage of their yearly cycle they are normally composed of an older pseudobulb and the current year’s growth with a single inflorescence arising from the base of the newer pseudobulb. The plant has neither leaves nor roots and the pseudobulb supplies all the needs of the inflorescence. At this time I water my plants but the plants seem to survive equally well with no water at all. I water them to avoid having the pseudobulbs become too withered. When blooming is getting close to finishing a rapidly growing bud will appear at the base of the newest pseudobulb. This is the signal I use to repot the plants. I take the plants out of the pots, I trim the old dead roots but leave the base of the roots still attached to the pseudobulb to help anchor the plant in the new potting media.


The plant should be repotted just as the new growth starts developing its roots. I tend to repot at an earlier time when the new growth is pretty small but I do this mainly because I have on occasion damaged the new growths when I have waited too much to repot them and they are quite large. I have used several types of media such as potting soil, peat, compost, sand and I have not noted much difference in the growth response of my plants. However there are two things that seem to have a great influence on the growth rate of the plants. First is the inclusion of manure in the potting media. If the media is around 1/3 manure the plants do much better. You might want to ask, Isn’t that a lot of manure on the media? The answer is, yes, but that what works for me. Second if the media is loose and easily penetrated by the roots the plants grow more vigorously. Calanthe in compacted hard to penetrate media produce smaller root systems and stay smaller than those grown in fluffier media. When the plants are in full growth mode I give them daily watering and in those cases when I have a large pot full of pseudobulbs I will even go so far as to put a water dish under the pot to ensure that there is enough water to sustain their rapid rate of growth.


I divide my plants every time I repot them, Calanthe is one of the few orchid genera where a single pseudobulb can produce a new full sized new pseudobulb without the back up of older bulbs. Depending on my mood I might plant them one bulb to a pot, two or even a dozen in a single pot. If they receive the proper level of light and watering they will do well in any number of combinations. I don’t give them the water soluble fertilizer when I water them since the manure in the potting mix takes care of their fertilizer needs for the whole growing season.


My plants produce their growths during the summer when local temperatures can climb into the nineties and it rains almost daily. They bloom in the colder and drier part of the year when a whole month can go without significant rain.


They get full sun most of the morning and shade from 11:00 am on. Exposure to too strong sunlight burns the leaves and leaves them covered with bleached yellowish areas and dead spots. But plants grown in the shade are weaker and bloom poorly. It takes a bit of experimenting to determine which exposure best suits the plants in your location. I try to achieve the elusive slightly yellowish and yet not covered with dead spots areas that brings the best blooming results in my area.


I treat my Calanthe Grouville the same way as Cal. rubens but since the pseudobulbs are much large I make allowances for a larger adult size. Cal. Grouville can form large avocado sized pseudobulbs and produces beautiful pleated leaves. It grows enthusiastically under tropical conditions and sometimes produces two growths at the same time from a single pseudobulb. Its inflorescences can get much larger than those of rubens reaching a meter or more. It produces its relatively short lived flowers in sequence as the inflorescence elongates. The inflorescence can have one to three flowers at a time. My personal problem with Cal. Grouville stemmed from its proclivity to proliferate at a furious pace if given good care. Since every year the number of pseudobulbs duplicate I found myself with dozens of plants. Because these plants are not small, finding a place to put them became a chore. I recall one year that I had so many that I gave every member of my orchid society a pseudobulb to plant and grow.


Cal. Grouville can stay in bloom for months but the inflorescence is at its most beautiful when it is opening its first few flowers. Afterwards it becomes leggy, in some cases the inflorescence can arch downward and eventually reach the ground which doesn’t stop it from continuing to bloom. This Calanthe is particularly striking in massed displays in which many plants are shown together.


My Calanthe seem impervious to most diseases but sometimes the pseudobulbs can rot if kept too wet when they are supposed to be in the dry season. One peculiarity of these plants is that sometimes the pseudobulbs produce small plantlets from their tops. Calanthe rubens pseudobulbs have a constriction in their top half, this makes the top half vulnerable to snapping off from the plant if the pseudobulb is handled too roughly. But if this shouldn’t cause alarm as the snapped top can be planted on its side and it will eventually produce a plantlet from its top that can be reared without difficulty.

Phaiocalanthe Kryptonite an easy to grow terrestrial orchid



Four inflorescesces of Phaiocalanthe Kryptonite 'Ursula'



Phaiocalanthe Kryptonite 'Chariots of Fire'

Phaiocalanthe Kryptonite 'Ursula'  an almost fully expanded flower

Phaiocalanthe Kryptonite 'Ursula'  newly opened flower.

A fully expanded, several days old flower

I have a wide variety of orchid genera, all of which delight me with their lovely colors and wonderful fragrances. These genera vary enormously in their cultural needs and ease of care. If one were to rank them according to the amount of care they need Phaiocalanthe Kryptonite would rank as one of the less demanding of all my orchids. However, it is after all an orchid, and because of this it does have certain quirks that need to be accommodated if one is to get the best possible performance this particular plant. In the next few paragraphs I will detail some of the things I have learned from cultivating this Phaiocalanthe.

I grow my plants on the east side of the house. There they get full morning sun filtered through the leafy branches of some huge teak trees and then shade from around 11 am until sundown. I can vary the amount of sun the plants get by moving them farther or closer to the shaded area under the teak trees. In general the plants do better in bright light but the leaves burn and become marked and unsightly when exposed to the full midday sun. So the key here is experimenting carefully with the amount of full sun that the plants can tolerate in your locale. My experience has been that plants grown in the shade will look wonderful but bloom weakly and with few flowers. Plants grown with some morning exposure to the sun will grow and bloom well but the leaves can develop some light spotting. Plants exposed to full sun for many hours bloom the best but look awful with ragged yellowish leaves full of dead spots. Some of my friends deal with this problem by cutting the leaves when the inflorescence is just about to open its first flowers. I have never done this but it might be worthwhile if you want to exhibit the plants in a special setting where the damaged leaves would detract from the beauty of the flowers. I have no idea how this affects the vigor of the plant but my guess is that it might weaken the plant and shorten the blooming period. This however is just a guess. I try to balance the desire for many flowers with the need to keep the leaves presentable. I am not always successful at sticking a perfect balance but most of the time my plants do well enough.

In my location the plants are exposed to temperatures that range from 95F in the most sweltering part of the summer to 55F for a brief span of time at the peak of the tropical winter. My plants seem indifferent to local variations in temperature and grow as well in summer as in winter as long as they are cared appropriately.

Humidity in my location ranges from 70 to 100%. At the peak of the rainy season, in summer, the plants can get thoroughly soaked every day for several months. In the peak of the dry season it can go for a whole month with no precipitation and humidity can drop to 40% at midday. In the dry season my plants are watered once or twice a week and seem equally at home sopping wet as with a marked wet and dry cycle and its attendant fluctuations in humidity.

When the plants are in their growing phase I water them every two or three days depending on the weather. As long as the plant is growing I like to keep their media wet, not moist or evenly moist, wet, wet, wet. When the new growth has reached full size I cut down on watering and in the dry season I might stop watering them if the plant has shed its leaves and become dormant.

Some people I know give their plants liquid fertilizer on a regular weekly or monthly basis, I don’t do this. I incorporate the fertilizer in the potting media and this takes care of my plant’s fertilizer needs.

Since these plants are terrestrial I plant them in a suitable terrestrial media. I mix my own media but they can grow with varying degrees of success in most potting soils. This is the composition of the media I use to pot this orchid. One fourth of the mix is compost from my own compost pile. I have an eight foot tall roll of metal close to my kitchen door and every day I deposit on it kitchen scraps, along old newspapers, waster paper, shredded bank statements and just about everything organic that can be composted except meat and lard. It smells very little and thank to a veritable army of local anolis lizards it mostly fly free. Half the potting mixture is composed of red lateritic soil, this sound exotic but this type of soil is available in practically unlimited quantities all around my house. The last ingredient to the mix is one fourth of manure, horse of cow work equally well. I also add a bit of sand to the mix to keep it from compacting too much. I mix all this in a tub of about twenty gallons, I mix only the amount I am going to use at the time.

Phaiocalanthe Kriptonite is simple to cultivate and only makes modest demands of care during the year but there is one thing that this plant really needs to do well. Unless they are repotted each year in fresh media my plants start to decline, lose vigor and size, and start blooming poorly. I think the reason for this is that these plants are such voracious feeders that they exhaust their soil of nutrients in a single season.

Dendrobium primulinum 'DeLeon' an interesting plant

Flower with nearly round lip

flower with a very small scoop like lip

Large flower with oblong lip that has a ridge in the middle

This is a flower that is just opening it will expand until it look that the one in the photo over this one

A fairly good blooming althought the presentation is not the best

Large plant growing in a fairly small wire basket

I brought this interesting Dendrobium a few years ago from Eli Orchids in Utuado, a town in the mountainous interior of the island of Puerto Rico. When I got this plant it was labeled as Dendrobium primulinum var. Leon and for lack of a better name I kept this ID and photos of this plant taken by me can be seen in several orchid forums. However when it bloomed the flowers were oddly different from what most books and Internet photos identified as typical primulinum. I found photos of flowers that had some resemblance to those of my plant, the flowers were those of variety Assamicum. However on closer inspection the resemblance proved to be superficial. Compounding the problem of identification was the strange proclivity of this plant to produce flowers of widely differing sizes and shapes. Even worse some flowers expand quite a bit and may look one way freshly opened and another after they have been open for a week. A few days ago, with the help of Brian Monk who answered a question I posted in the Orchid Source forum, I finally learned that the true identity of my plant is Dendrobium primulinum DeLeon.

But the doubt I had about this plant identity plant, when I first bloomed it, piqued my curiosity so I studied scientific descriptions of the flowers of primulinum to better understand this plant. What I found is that the appearance of the flowers of this species is more variable in color and shape than one would guess judging from the characteristic of those exhibited and grown in the United States. The plants in the US, at least judging from photos of collections and exhibitions used to be, until recently, relatively uniform in appearance. I would like to add that primulinum now has been lumped with cretaceum and the plants are called Dendrobium polyanthum.

The form of primulinum commonly pictured in those books and photos that have been available to me has thick, arched canes that are relatively short. The flowers in these plants have hairy lips of a light yellow color, the sepals and petals are varied shades of mauve. In the lip, usually to the side of the column there are purple lines that have a varying extent in different clones. I have occasionally seen plants of this type in local collections, but I have never seen one in bloom anywhere in PR.

About four years ago a new type of primulinum appeared locally. This new type was part of a huge importation of all types of Dendrobium for the spring show of the PR Orchid Society show. It is clear plants of this type were also imported into the US as photos of the flowers of plants of this type cropped up in the Orchid Source forum. This new type has large flowers with a beautiful bright yellow color covering the center of a white lip, the sepals and petals were a delightful soft pink. But this new plant didn’t resemble DeLeon at all. The vegetative parts of this plant were different from De Leon and the thick short canes of the primulinum I had known previously. This plant resembles those plants known in Japan as var. giganteum.

Information on primulinum DeLeon is pretty sparse. I did several Internet searched and frustratingly and vexingly the results of the searches were either posts that I had made about this plant on the various Internet orchid growing forums or the advertisements of the vendor that sold me this plant. Thanks to Brian Monk I learned that this plant earned a certificate of cultural merit for its owner back in 1968, the plant exhibited had 101 flowers.

My plants grow well without any special treatment but are curiously varied in their blooming. This is a bit surprising since all are descendants of the same plant. Some produce large flowers with huge round white lips other produce smaller flowers. At times a cane can have large flowers near the top and smaller flowers near the tip. The lips of some of the flowers are very round others are oblong and some even have a ridge down the middle. It is unclear what causes this variation in the flowers but in general older plants with several older mature canes produce better flowers than younger plants with just a few small canes. A peculiar characteristic of this plant is that the first few leaves of the new canes can have a bright reddish or purplish tint in the margins, this I have not seen in any other Dendrobium of this type that I have grown.

This plant doesn’t seem to need much rooting media to subtract enough water and nutrients to prosper an achieve a good size. One of my plant has six healthy new canes from three to four feet of lenght and several older canes all growing from a mass of media two inches thick and six inches wide. However it is to be noted that this plant gets drenched every day during summer and fertilized weekly for as long as the canes are producing new leaves. This plant usually finished its growth cycle October and starts shedding its leaves by November.

Some years the plants blooms wonderfully, others they barely produce one flower or two. But I enjoy so much the flowers when they are produced that I don’t mind the fact that some years some plant fail to bloom. I have been looking at the wonderful plants that have been awarded in Japan and I have realized that the flowers of my plants would look even better if I did some grooming of the canes before the buds open to prevent crowding of the blooms. I am looking forward to next year blooming to see if I can make the 2011 blooming the most beautiful and elegant ever.