Wednesday, December 18, 2013

Dendrobium wardianum, culture notes

I had always been curious about Dendrobium wardianum but I had never had the opportunity to grow this plant because I could not find sources for it.  But in 2012 I found a source that would ship plants to Puerto Rico.  I ordered two plants.  When they arrived I found that they were tight;y wrapped in sphagnum moss against a flat piece of wood.  I never bury the stems of my plants in sphagnum moss, so I decided to remove one plant from the mount.  The other one I left untouched, just in case.

The plant I removed from the mount turned out to be three seedlings planted so close to each other as to appear to be parts of a single plant.  I carefully extricated their roots from the sphagnum.  It was clear they had not spent any appreciable time in the sphagnum as the roots came out easily.

The strongest seedling was given its own basket.  It had a nice fat, two inch cane.  I was very careful to keep the stem away from the media and to leave all the roots exposed.  I prefer to leave the roots of the Dendrobium seedlings and keikis exposed.  But the stem was close enough to the basket that the new roots would have to travel only a short distance to reach the media

The smaller, weaker seedlings were put in a basket together.  Note that the basket has a layer of medium sized bark, sphagnum moss and then another layer of medium bark.

A year after they were planted the seedling have grown in various ways.  The strongest seedling started growing in the spring and eventually produced a seven inch cane.  But it didn't pause for the year, instead it initiated another cane, this cane topped out at eighteen inches, a near adult cane.  The two smaller seedlings have grown much slower, one is still quite small.   I never watered these plants, they got all their water from rainfall.  They were fertilized but only when they were growing, the fertilizer was one high in nitrogen.  The other plant, the one I left in the sphagnum moss, rotted away completely, during the start of the rainy season. At first the leaves turned black and then pseudobulbs  also turned black and collapsed.

Here is the largest plant with its nearly mature eighteen inch cane.  It is still too early to determine if this plant will bloom under my climate conditions but is is clear it can grow well in my garden,  I will not subject this plant to a rest period until it has at least two full sized mature canes.  The two smaller plants will be moved to a sunnier location since they now have an established root system.  Hopefully this will help them grow larger and stronger.  If the larger plant produces another large cane in 2014, it will be given a rest period of decreased watering and more sun exposure.  Whether this will be enough to make it bloom, remains to be seen.

These are the approximate values for rainfall in my location in Rio Abajo

                             J       F      M       A       M       J       J       A       S      O      N      D
Rainfall (mm)       99   76     84     165     283    155   141   216    237   233  176  135

(inches)                3.9   3.0    3.3    6.5    11.1    6.1    5.5   8.5      9.3    9.1   6.9   5.3

1 comment:

Martín S. said...

Hello Ricardo
Any updates and pictures on your Den. wardianum and their culture since this post?
I have three of them - all grown outside in Southern California. One is grown in a 2" plastic pot with medium orchid bark & perlite, and the other two are mounted on cork with sphagnum moss. None of mine get larger canes than 4-5 inches, and I'm puzzled as to what I'm not doing correctly. They get the typical dry rest for the winter, and temps range from 38'f at night at the coldest, to 90's at the warmest. Mine grow okay, but they just don't thrive, and I really want to figure out why.