August 16, 2016

Repotting An Orchid, Mistakes To Avoid

I couldn't delay any longer. My cattleya hybrid was in serious need of repotting. The roots were fused together and growing outside the pot. The pot itself was miniscule, only meant for a seedling I imagine. The plant looked altogether droopy. The main reason for my hesitation is lack of orchid potting medium.  Here in Kinshasa you can't just walk into the local nursery and buy fresh potting mix. You have to get creative and make your own.

Fortunately a few weeks ago I found a dried coconut husk on the ground which I saved for future use. I visited a nearby construction site and collected up some wood chips. After cutting the coconut husk into small pieces I soaked it along with the wood chips in water for several hours. I took my orchid out of its tiny pot, washed the roots then began stuffing the roots with coconut husk. I layered wood chips on the bottom of the pot then set my orchid in the pot while squishing in more wood chips and coconut husk. I can hear the experts gasping in horror. This is NOT the way to repot an orchid and they no doubt can guess the disaster that followed. Within a couple of days the potting medium was moldy and mold was starting to grow on the roots. Now my little cattleya was in a state of emergency!

What were my mistakes? 1. Wood chips instead of bark chips. 2. Too much water-retaining coconut husk. 3.  Waterlogging the mixture and 4. Packing it too tight in the pot. These are mistakes to avoid when repotting an orchid.

Back to the drawing board. This time I went and collected bark from the felled trees at the construction site.  I chopped them into small pieces, washed them with disinfectant, covered them in cinnamon and let them dry out for a few days. I gently removed the orchid from its pot and washed and disinfected it. More drainage holes were added. Meanwhile I carefully washed the roots and snipped off everything that looked dead or rotting. I adjusted the ratio of bark chips, coconut husks and miscellaneous dried seed pods to about 60/30/10. This time I did not presoak the mixture. I simply gave it a good watering. A few days later I watered and fertilized.  Now, after two weeks my orchid is looking perky and is growing new roots. Orchid repotting crisis averted!

August 11, 2016

Orchids of Hawaii

Dendrobium Hybrid, photo taken at World Botanical Gardens, Hilo, Big Island, Hawaii

Who can help but associate orchids and hawaii?  I am fascinated by the orchids of hawaii. When you step off the plane in Honolulu, that heady combination of humidity and tropical florals overwhelms the senses immediately.  As you are greeted with a welcome lei of purple and white dendrobiums, the link between orchids and hawaii is indelibly etched in your mind. As you tour the islands this association is strengthened as you see the roadsides dotted with spathoglottis and various dendrobiums and vandas growing in nearby trees.  No visit to Hawaii is complete without a tour of  botanical gardens bursting with colorful, showy orchids of many different species.  And aren't Hawaiian orchids being exported all over the world?  There are over 60 potted orchid growers that are members of Orchid Growers of Hawaii. But, did you know that Hawaii is home to only three native species?  That's right - three!

After some interesting research and reading I learned the difference between Hawaii's native species and the species that have "gone wild".  According to the US Department of Agiculture a native species is defined as:
"A plant that is a part of the balance of nature that has developed over hundreds or thousands of years in a particular region or ecosystem. Note: The word native should always be used with a geographic qualifier (that is, native to New England [for example]). Only plants found in this country before European settlement are considered to be native to the United States." Whereas a naturalised species is defined as "A non-native plant that does not need human help to reproduce and maintain itself over time in an area where it is not native."

The three native orchid species of Hawaii are Anoectochilus sandvicensisLiparis hawaiensis and Platanthera holochila. The anoectochilus sandvicensis and the liparis hawaiensis are considered rare.  The platanthera holochila is endangered and is part of the Plant Extinction Prevention Program of Hawaii. These native species grow in forests and bogs at high altitudes.  They have a very discreet appearance compared to popular favorites but are unique treasures of the orchid world.

So what about naturalized orchids?  Many of these species were introduced over the years and with the introduction of pollinators, such as the honey bee, some species started to grow and thrive in the wild across the hawaiian islands.  According to a fascinating research paper, by James Ackerman, there are a quite a number of orchid species that are considered naturalized including:
  1. Arundina graminifolia 
  2. Epidendrum ×obrienanum
  3. Cymbidium dayanum
  4. Dendrobium crumenatum 
  5. Habenaria rodeiensis
  6. Dendrobium antennatum 
  7. Phaius tankervilleae
  8. Dendrobium cf. mirbelianum 
  9. Polystachya concreta
  10. Dendrobium nobile type 
  11. Spathoglottis plicata
  12. Dendrobium antelope type 
  13. Vanda tricolor
  14. Dendrobium bigibbum type
  15. Zeuxine strateumatica
No wonder the hawaiian landscape is peppered with so many beautiful orchids! Hawaii has a very favorable climate for growing many different orchid species and the Big Island has rightly earned the name The Orchid Isle! Many of us have had our awareness heightened and appreciation increased for these amazing plants because of its strong associations with this tropical paradise.