Dendrobium purpureum Roxb. 1820 var. alba, first blooming 2016

This is the first time this plant has bloomed for me.  The plant is still small, I expect that as it get bigger the inflorescences will be larger and fuller.

Dendrobium bullenianum Rchb.f 1862, first flowers in my garden

I have found that this Dendrobium is easy to cultivate in Puerto Rico.  The plant needs a well drained medium, abundant watering and regular fertilizing to produce its long canes.  It does equally well in the coast and in the mountains. Where I live, at 1000 feet of altitude temperatures only go under 60F at night during a short spell in winter, it doesn't seem to bother this plant.  I prefer to cultivate upside down like I do my Den. anosmum so that the mature canes hang down as they do in nature.  This is the first blooming of this species for me, the plant is still small and young.  I expect that when it reaches its adult size it will produce its characteristic many flowered globular inflorescences.  

Dendrobium anosmum var. huttonii, an update on my plant

For the last seven years my plant of this species grew vigorously and bloomed well.  Unfortunately, I moved it to a shadier, wetter spot than what it was used to because I wanted to put some other plants there.  As a result the base of the plant stayed sopping wet for weeks during the rainy season and it died.  Fortunately the plant has four large keikis that will be repotted to individual baskets as soon as they finish blooming.  Although the mother plant base died, the keikis are so large, all of them bloomed.
Here is a link to how I cultivate this plant.

http://ricardogupi.blogspot.com/2008/10/dendrobium-anosmum-var-huttoni-culture.html

Dendrobium devonianum, a challenge to grow and flower in the mountains of Puerto Rico

Years ago I brought this plant of Dendrobium devonianum after seeing a stunning photo of a flower in the Orchid Source forum.   As it often happens to orchid growers, the beauty of the flower overwhelmed any apprehension on whether the plant would grow under my climatic conditions.   In 2008 I acquired two small plants.  Both were just a few inches long and their roots were wrapped in coconut fiber.

The larger plant grew vigorously, when it bloomed I was very disappointed to find that it was actually Dendrobium aduncum.  The little plant grew slowly and produced comparatively weak growths.    The thin, wiry canes that it had didn’t give me too much confidence in its survival.  I was so concerned at the thinness of the cane that I measured the stem near the base of the plant and found that it barely was .8 millimeter wide.

Eventually, in 2011 the orchid produced a cane that seemed large enough to bloom.  But no flowers were produced.  Five years after it had arrived at my garden, in 2012 the orchid finally bloomed. It produced two short lived, pale flowers.  I was happy that it bloomed but sad that the flowers lasted just a few days.  The plant didn’t bloom in 2013.  In 2014 it has produced five flowers, its best performance yet. 

This orchid has proven to be challenging to keep in good shape in my garden.  It has lost canes for no clear reason.  I grows slowly compared with my other pendent Dendrobium.  Its leaves are short lived which means only the last foot or so of the growing cane is leafy at any given moment.  

In a location with a more temperate climate this orchid would do much better.  Given its spectacular flowers, and the fact that there are many growers in the northern countries which can give it the moderate temperatures it likes, I am surprised that this Dendrobium is not more popular.  The Bakers in the book on Dendrobium report that growers say this plant is difficult to grow, something that my own experience confirms. Most of the plants I have seen in captivity outside its native haunts don’t seem to be in a much better condition or more floriferous than mine.

In my experience this plant is not for the novice or neglectful grower perhaps unless you happen to live in those parts of Asia where this plant is native.   Even with the best care this plant may prove a disappointment if you live in an area where the local temperatures are uniformly high for most of the year. 

The plant is potted in a six inch wide wire basket.  It is potted in bark. It gets watered every three to four days.  It gets fertilized once a week during growing season and not at all between December and June.  It gets full morning sun but after 10:00 am it gets light filtered through the canopy of trees and palms.  It has never been repoted.  In my garden it blooms in May and June.

Grammatophyllum Jumbo Grand (Gramm. marthae x Gramm. stapeliiflorum)

This hybrid has pendent inflorescences just like the stapeliiflorum parent, but they are much longer than in the parent species.  The flowers combine the traits of marthae and stapeliiflorum in a way that I find pleasing.  This is not a plant for the windowsill grower or those with limited space.

Bulbophyllum tricornoides Seidenfaden (1979)

This is a species that is native of Thailand¹.  This orchid is not mine, it is cultivated by a friend that lives in the town of Aguadilla, Puerto Rico.   He lives a few hundred feet from the seashore, this means that humidity is good year round.  This is an important consideration with Bulbophyllum because some species don’t grow well if humidity is low.  His plants are hung over several aquariums which also helps maintain good humidity.  In his location temperatures are always warm and in summer they can go over 90F.

This plant grows well and blooms abundantly in coastal Puerto Rico.  As you can see in the photos it will roam all over the pot or basket and won’t hesitate to send growth under the basket if it is grown in one.   The inflorescences can be erect or hanging.   The plant can produce several inflorescences at the same time if in good condition.  It is grown under saran   cloth.It is interesting that, although Bulbophyllum is not a particularly popular genus among the average orchid grower, when looking at the collections of more dedicated growers you can find all sort of species that are rarely seen locally.  

 

¹ Siegerist, Emily S.  2001.  Bulbophyllum and their allies: a grower’s guide

The stunning Dendrobium devonianum

A few years back I saw a photo of a flower of Dendrobium devonianum that was so spectacular that it took my breath away.  The photo was by Dale Borders and it was posted in the Orchid Source Forum.  I wondered if I could grow it since by all indications this was a high elevation plant whose range encompassed areas with more temperate weather than PR.  I asked Dale how he cultivated this plant and he told me that he grew it next to its Dendrobium primulinum.   Since I had a few years of experience growing and blooming Den. primulinum I decided to try this plant.

When I brought my first two plants of Dendrobium devonianum, back in 2008, I must confess I was underwhelmed by the sight of the plants.  The larger plant seemed scrawny, I had expected that, but the smaller one with its larger cane barely six inches long, was so unimpressive I thought it might not survive the process of becoming acclimatized to my local climatic conditions.  Eventually both plants started producing new growths, the larger one with vigor, and the smaller one at such a slow pace that it was glacial in comparison with the first one.  This pattern repeated itself every year, the larger plant growing ever faster and the smaller one barely making progress.  In 2010 I was quite excited to see buds on the larger plant, alas I was utterly disappointed when the larger one produced flower buds and it became clear it was Dendrobium aduncum.   To my defense I have to say that Dendrobium devonianum is an exceedingly rare plant in Puerto Rico and I had never seen one so could not tell it from Den. aduncum on sight.

The smaller plant kept growing exasperatingly slow and producing absurdly wiry stems.  The incredible thinness of the stem near the base is almost unbelievable.  The cane produced in 2010 was eight inches long but the width near the base was .8 millimeter.  Yes that is no typo, I actually used a caliper to measure it, the stem was less than a millimeter wide!  Even the 2011 cane, which is the one that bloomed measured three feet eight inches long but was a tiny fraction of an inch wide near the base of the cane.  To put it in metrics, the cane near the base is 1.2 millimeters wide, the cane is 1.17 meters long, around a thousand times bigger.  I want to clarify that the very thin part is only a short stretch near the base of the plant,  the rest of the cane is thicker, a little less than half a centimeter thick.

In 2011, to my surprise the plant started producing a new cane with previously unknown vigor.  The cane kept getting bigger and bigger unlike previous ones that would stop at a few inches after lackluster growth.  The cane eventually measured, as noted previously more than three feet long, which was five times bigger than the size of the previous cane.  Eventually the cane lost all its leaves and all I had to do was wait for the blooming season to come around.  And I waited, and waited and waited.  By the start of May all my other deciduous Dendrobium had bloomed, I assumed that the plant would not bloom.  One day in the first week of March, as I was watering the plants, I noticed that there were some slight swellings in the side of the cane.  By then the local rainy season had started and I wondered if it was really going to bloom or that it was going to produced keikis. 

The next few weeks were depressing. The plant kept producing flower buds and they would start to develop but after a while they would turn pink and fall from the flower.  This happened seven times.  I despaired of ever getting to see the flowers.  The fact that this is a Himalayan Dendrobium and at the time the plant was producing the buds the temperatures were sweltering and humidity sky high.

The last two buds managed to develop all the way to maturity and opened on May 5.  They are so beautiful that all frustration was forgotten.  I expect that as the plant develops larger canes and an even more extensive root system it will be able to bloom better.  The new growth is already nine inches long and it is slightly huskier than the preceding ones, the quoted size for the cane of this species is three feet long, but I expect this plant to exceed this size in the 2012 cane.

This is not a species for a beginner, particularly in Puerto Rico.  It demands patience and consistent care.  I grow this species at an altitude of 1000 feet in the interior of PR, I don’t know how it will fare in the coastal lowlands which in summer can reach high temperatures in the nineties degrees range.  

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!

Dendrobium Adastra a hybrid of anosmum and cucullatum

I brought this plant many years ago in a Puerto Rico Orchid Society show at el Coliseito Pedrin Zorrilla.  When I brought the plant it didn’t have an ID but given its distinct flowers it was easy to identify it using the sources available over the Internet.  This orchid is a hybrid of Dendrobium anosmum and Dendrobium cucullatum (pierardii).  I have seen a number of plants of this hybrid and there is a certain degree of variation on flower size, the color has been the same in all the flowers.  The plants I have seen fall into two broad types, the ones that favor the flower size of the anosmum parent and the ones that are on the cucullatum parent side of the spectrum.  The plants that have flowers that are more similar in size to anosmum tend to produce less flowers that the ones that favor cucullatum, which has smaller flowers.  I personally like the type that produces the smaller flowers.  None of the plants I have seen have had any fragrance that I could detect. 

This plant is a vigorous grower under my local climatic conditions and the care it receives is the same that my anosmum plants are given http://ricardogupi.blogspot.com/2008/10/dendrobium-anosmum-when-cultured-so.html.

To my surprise I have found that my clone of this plant is less tolerant of exposure to full sun than the clones I have of the parental species.  Plants grown with an exposure to a few hours of morning sun are smaller and weaker that those that are under shadier conditions.  It is unclear whether this is a result of an endemic susceptibility of this hybrid or a particularity of my clone.

My plant produces flowers that are brightly colored when they open but that become lighter in color as they age.  As a result the plants are at their most beautiful in the first few days after the flowers open.  My clone of this hybrid produces canes that are shorter than those of most anosmum and cucullatum clones I have even though it is grown under the same conditions that they are.   Since some of my cucullatum and anosmum plants can produce six feet long canes I can only surmise the plants that were used as parents for this hybrid were of a smaller stature. This plant produces keikis fairly frequently in older canes and the keikis grow well with routine care.  Sometimes the base of the older canes succumbs to rot but the rest of the cane stays alive.  When this happens I put the cane in a shady and humid area and very often the cane will produce one or more keikis.

Dendrobium anosmum and their relatives, warning signs of cultural trouble

Vigorous and healthy root growth, note that the cane producing the roots is twice as thick as the previous growth

New roots are white older ones are grey green, absence of root growth is a clear signal of trouble

Fungal and bacterial infections can strike with astonishing speed and virulence, this is all that remained of a specimen plant of Dendrobium formosum var. giganteum.  If the gravity of the situation had been recognized on time at least some pices would have been saved for propagation

This Dendrobium nobile has been growing for many years in an avocado tree under hot tropical conditions.  It has never bloomed although in all aspects it is mature plant fully capable of blooming.

Dendrobium nobile blooming in a shady and cool location.

A Dendrobium phalaenopsis derived hybrid which lost all its roots due to inappropiate potting, all the old roots are dead but some new roots are showing their tips near the base of the canes.

The buds at the base of this canes are dead so the plant is producing new growths from buds higher up in the cane.

The base of these canes of Den. primulinum was damaged by sunburn and died.     The canes were bent so that the keikis produced by them can attach themselves to the basket.  Notice the many keikis and their abundant root growth.

Den. phalaenopsis hybrid grown with its roots exposed.  Note the abundant flower production and the fully leafed new cane.  It is normal for older canes to lose their leaves after the first year.

Under good care some keikis will bloom even when they are not affixed to anything

When they are growing at their preferred temperature and lighting range, well cared pendent dendrobiums grow vigorously, without any particular trouble and bloom reasonably well. But when they are grown under conditions that are unsuitable for them several things happen that serve as a warning signs that the plant is not doing well. I will detail some that I have learned from the bitterest experience. This is a work in progress and I will try to add information as time permits.

I. When your plant needs a colder rest period to bloom than you can provide.

If a plant needs a colder rest period to bloom but otherwise the conditions are to its liking you will get an endless production of handsome canes, which will be plump and healthy but will never bloom or even get in bud. Because circumstances prevent them from blooming these plants channel their energy into growth and can produce quite large plants. One Den. chrysanthum I have eventually produced a ten feet long cane. This particular plant has never produced even a single bud under the local climatical conditions. Dendrobium nobile will not usually bloom in coastal Puerto Rico but will bloom nicely if moved to locations about a 1,000 feet high in the mountain areas and in certain colder inland areas. There are plants here and there that bloom under conditions that are not in their usual preferred range but usually they do so erratically or poorly.

II. When the temperature is not in the preferred range for growth.

The first signs of trouble in this case is usually a lack of root growth. Unfortunately some pendent dendrobiums can survive for many years growing weakly and with root systems that barely sustain whatever meagre growth they manage. It can happen that the plants perk up and do produce good growth during brief times when conditions are to their liking, but as soon as temperatures drift out of their preferred range the plants weaken again. I brought a Den. falconeri that managed to survive ten years by growing acceptably during the brief weeks that local temperatures dipped and then sulking the rest of the year. Strenuous efforts to sustain this plant only lengthened the agony. Eventually the plant dissolved into a mass of tiny canes and diminutive keikis that were too weak to survive the summers heat. Keiki production on a a same year growth is also a very bad warning sign. It usually means that the plant inability to produce roots has made it transfer its energy to keiki production.

III. When it is not getting enough sunlight

If your plant is not getting enough sunlight to bloom properly you will probably get a few blooms right on the tip of the cane. A plant that might produce dozens of blooms might only produce two or three. The canes themselves might get to be abnormally long and thin. The leaves will have a deep green color.

IV. When roots are not entering the potting mix, or holding the mount.

This probably mean the mix is unsuitable for the plant because it has some characteristic that is inhibiting or killing root growth. A friend of mine accidentally killed many of his orchids by mounting them on the wood of a plant whose wood is permeated by a substance this plant secretes to kill other plants that  might compete with it for food or sunlight.  

V. A growth coming from a cane other than last years cane, if last year cane doesn't grow.

It probably means that the base of its newer cane is dead and the plant is trying to keep alive by producing growths elsewhere. In some plants, (this is an specially insidious occurrence in pendent dendrobiums) a cane that has shed its leaves can continue attached to a dead base without any obvious signs of distress for months before decay reveals that the base is dead.

VI.When a cane suddenly stops growing in the middle of producing a new leaf.

Usually means that something has severed the connection between the growing tip and the base of the plant. I have seen this happens when an insect gnaws the middle of a cane and makes a cavity but leaves it mostly attached to the base on the sides of the cane. This can cause the death of the whole cane, not just the tip.  On some ocassions this can signal a bacterial or fungal infection of a stealthy nature that only becomes obvious when the cane starts to decay rapidly at a time when it should have been growing.

VII. Blackened and sunken areas between the base of the plant and the lower part of the cane.

Can mean sunburn to this area, can result on the death of the plant but the survival of some of the canes.

VIII. Profuse keiki production on plants that normally produce them sparingly.

A sign of root loss, or of loss of the buds at the base of the plant.

IX. A weaker cane than the previous year's cane.

Plant is not getting what it needs to grow well, common in newly repoted plants that have suffered severe root loss and plant adjusting to new environments.

All this information is courtesy of the need to unwind after an unexpedtedly streesful day at work.

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.