Question
I've read that you can cut off the arms of some cacti and re-plant them to grow another plant.  Is this right and which type of cacti can I do this to?

Answer
Hi Andy,
Thanx for your question.  Almost all cacti can be propagated vegetatively (using a cutting from the main plant).  It must be a separate arm and one cannot simply carve a piece out of the cactus and expect it to grow.  If there is a separate growth developing on the major growth area allow it to become large enough where it can safely be removed from the parent plant.  Use a sharp knife dipped in bleach (to prevent disease) and place the cutting on its side on a paper plate until the cut area "heals" over or forms a "callous".  If you don't allow the cut area to dry up and "heal" the cutting will probably rot in the growing medium.  It should only take a few days for the cut to heal over and most cacti cuttings will survive for months without being planted.  I have had pads from prickly pear (Opuntia sp.) survive for a year without being planted.  Anyway, once the cut has healed.  use a good cactus potting soil and gently place the cutting deep enough into the soil so that it remains upright (but not too deep).  Don't over water.  Let it dry out and then give it a little water but be very careful not to leave the soil soggy.  I hope this helps.
Tom