Question
I purchased an Oncidium that was in bloom and had one pseudobulb. I went
to repot it and to make a long story short I broke the pseudobulb from the
bulb with the blooms. All the roots except one root that is not impressive was
attached to the pseudobulb. I would say that it has no roots now. I potted it in
bark and less than 20% charcoal and left the pot dry. Is there anything I can
do?  The blooms are large and quite beautiful.

Thanks

Marc

Answer
Hello Marc,

That is a definite "oops!".  You didn't mention where you live or where and how you are growing it so I'll keep things fairly generic.  

All may not be lost (hopefully) and it will survive.  If all of the buds have opened, you have a choice: leave it alone and hope everything stays okay or cut off the bloom stem, place it in a bud vase with lukewarm water and allow the oncidium to get on with trying to grow some more roots.  If you choose to cut it off, replace the water every few days to keep the stem in fresh water.  If you have 7-Up or lemon-lime soda, put a few drops in the water and it will be happy.  The flowers should remain fresh for several weeks with this treatment.  

When you repotted it, did you use the same pot or a new pot?  If a new pot, is it the same size as the old or is it smaller or larger?  With so few roots, it would be best to put it in as small a pot that will hold the remaining root and the pseudobulb will fit in.  Oncidiums prefer having their roots crowed within the pot, given too much room and they may end up rotten.  

Place it where it will receive bright morning sun until about 9 A.M. then bright indirect sun after that.  Temperatures between 55 to 85 F, humidity above 50%, light air movement and water when the potting mix becomes barely moist.  Until new roots grow, go easy on the fertilizer.  When multiple new roots are over 2 inches long, you can start feeding it regularly.  

Hope this helped.  Good luck and good growing.

Jim Kawasaki
San Jose, Ca.