When repotting, you need to plan ahead to the _next_ repotting. The general
idea is to leave room for 2-3 years' growth. [With bark, I wouldn't go more
than 2 years. With a non-decomposing medium like lava rock, you can go 3 or
even 4.]

But as previously mentioned, it's more important not to over-pot the roots.
A small plant -- or a plant with a small root system -- in a big pot will be
prone to staying too wet for too long, which invites root rot. Kenni

"Gail" wrote in message
ink.net...
Some of my orchids have been in the same pot two or three years now. I
have read that they should be repotted (because the bark breaks down). How
do I know if they need a bigger pot along with new bark? Thanks in
advance.
Gail