Dendrobium Culture: Making a Den cretaceum specimen plant

 

Some years ago, I started cultivating a Dendrobium cretaceum plant with the aim of eventually getting a specimen plant with many flowers.  For aesthetic reasons I decided to cultivate the plant so that the canes hang from the bottom of the basket.   The orchid is planted in a way that is extremely different from what is the usual way of growing Dendrobium.   The plant was originally attached to the center of the bottom of the basket.  That way the roots would grow up into the potting mix and the canes would grow downward.   That is the exact opposite of how these plants are grown.    The basket is six inches wide and three and a half inch deep.  The potting media is bark, and fills the basket to a depth of two inches.   Den cretaceum is not a big plant so this arrangement allows plenty of space for it to grow for years.

There two-inch layer of media in the basket allows for plenty of air to reach the roots.   This is a very important detail.  You would think that is a very small quantity of media for a plant that one eventually wants to become large and bushy.  But due to the local climatic conditions it is the perfect amount.  The reason is that during summer and fall in my locality it rains almost daily.   At the peak of the rainy season the media can stay wet for weeks or months.   In a plastic pot this would mean a waterlogged media that would quickly become devoid of oxygen, will start rotting and turning into slush under the influence of fungi, bacteria, high temperatures and fertilizer.  

 To my delight, at the start of the 2023 growing season the plant, that usually produces four or five new canes every year, in a fit of exuberance, started producing nine new canes.   This is wonderful but it bring its own suit of problems.   First, all the canes are clustered and oriented toward the strongest source of light.   That means that the plant is self-shading.   This can result in that some of the canes will be spindlier and weaker.   To avoid that I moved the plant to a spot where it gets the strongest sunlight I can give it without burning the leaves.  Eventually as they grow the canes will spread out and the issue will resolve itself.  Because of the particular way the canes of Den cretaceum grow the leaves are not particularly vulnerable to burn if exposed to strong light.  The canes of this orchid arch downward, so that when the sun is at its strongest the leaves are edge on to the light.   A note of warning, while canes are capable of taking full sunlight, the base of the canes are prone to burning if exposed to very strong sunlight.  Fortunately, this is not a problem for me since the basket protects the tender bases from the sunlight.

If all goes well, by the start of the 2024 dry season, the canes will have reached their full size.  When the canes reach full size, I stop watering and fertilizing the plant, it gets only the scant amount of rain we get during the dry season.  The plant loses all its leaves and looks dead for a time.   In April I will start looking for the swelling flower buds along the length of the canes.  Then in May I expect the plant to produce a mass of flowers.  You can see on top the 2023 blooming.   The plant as it is now is in the photo below.