I got the Odontocidium Wildcat 'Bobcat' shown in this tutorial a couple of weeks ago for a steal, it was on clearance as it had already finished blooming. It had been by itself, on its own little windowsill, since then just waiting for me to get a chance to repot it properly. I repot all of my Oncidium and Hybrids (Odontocidium, Degarmoara, Wilsonara, etc...) this exact same way, so I hope it will prove some use to the readers.
I started out by soaking my plant in the sink for a few minutes while I gathered up my supplies. Soaking the plant helps loosen the plant from its pot and makes it easier to remove the old growing media. The supplies I needed were:
1. A clay pot.
I prefer clay pots because they are porous and allow better air flow to roots.
2. A growing media.
For all of my Oncidiums and Oncidium Hybrids, I use a standard store bought bark mix that I combine with a high quality sphagnum moss. I soak all of this in the sink before potting to allow the sphagnum to expand and to clean off the bark.
This is a concentrated fungicide/disenfectant/algeacide/viruscide such as Physan 20 or Consan 20. I mix according to label directions for plants. This is an important step to prevent disease and fungus from spreading from someone elses nursery to your home.
4. Garden scissors or shears.
We will use these to cut away the bad roots and any bad leaf damage.
5. River stones.
I use these in the bottom of every orchid I pot to encourage air flow and prevent root rot.
6. New tag.
You will want to go ahead and fill out a plant tag with the name of the plant and the repot date for future reference.
7. The plant.
Don't forget it!
Next I am going to remove the plant from is plastic pot. I will then gently work the roots out of the square they have grown themselves into, removing the old bark mix potting media along the way. Some of these roots will be difficult to untangle, just be persistant. I usually, and did in the case, finish by putting the plant in the sink and working free the last roots under running lukewarm water. It helps me get out that last bit of potting media.
Normally at this point I would spend a while trimming off dead roots, but my scissors didn't get a lot of work today. This was one of the healthiest root masses I've seen during a repot, and needed no real trimming work whatsoever. You can tell this by looking for discolored roots that the outer layer of velamin (similar to skin for a root) slides easily off the root itself (the root itself will be small and thin, similar to a piece of thread). Without any major root trimming, I went ahead and began soaking the plant in my Kill-bad-stufficide previously mentioned.
While the plant was soaking, I layered the bottom of my clay pot with an inch or so of river stones, and topped that with a small layer of the bark mix media.
After removing the plant from the fungicide, I thoroughly rinsed it again in the sink. Then I set it into about the center of the pot. (On top of the layer of bark mix we place on top of the river stones) This plant is in active growth,with new leaves shooting up from one side. To give it some room to grow, I orientated it so the new growth could easily expand into and fill up the pot.
Then, holding the plant in place, I sprinkled handfuls of the bark mix around the roots until I filled up the pot. Occasionally, I tapped the side of the pot to help settle the mix down in between the roots. The finished product should look like the picture above.
I rinsed the whole thing in the sink to help settle the bark mix and make sure the plant is stable in its new pot. Finally, I put my new tag into the pot and set the newly repotted Odontocidium in its new home.
I hope this helps somebody who has never repotted an orchid feel more comfortable with a first attempt. I know the first one I repotted made me nervous, as I was worried I would kill the plant. It is not a difficult process if you swing by the store and make sure you have the supplies you'll need prepared and ready to go. See more articles on Orchid Care
in the OrchidTalk Forums.