No it's not necessary. Look for the ones labelled "azalea pots" which have a
much lower form (not as deep). For shallower ones than that look for bulb
pans. For a catt that size a 18-20" wire basket w/ or w/o a liner would
narrow the bottom also. Another thing to do if you can't find or don't want
to do any of the above is simply to insert a number of inverted 3" plastic
pots in the bottom of your large pot to take up the extra space and give
excellent drainage. I love specimen plants but there's only so much room in
a greenhouse, no matter how big you make it, so you have to pick & choose
which go on and which get redivided.
Gary

"jtill" wrote in message
ps.com...
As pots get bigger they also get taller. Is this necessary? Big plants
I have repotted seem to have most of their roots within a few inches of
the surface. I have a 30 growth CATT and will repot soon, would a large
short, say 10 inch tall by 18 inch wide, pot be OK? I will use S/H and
the shorter pot would give better O2 at the roots it seems, and, Ray
may not have enough rocks to fill the tall one! ;-)). The clay pot is a
monster to deal with. It is tippy, heavy and I am betting there are few
roots that penetrate to the bottom, and, this is a TALL plant. What do
you think? If, when I dump it out,there are roots at the bottom I'll go
back into the same pot.
Joe T
Baytown/Houston