Question
I'm in zone 7 and have a very large white calla (AETHIOPICA) in a 15" square pot that has been green and growing for 3 years.  This past winter in my small greenhouse it bloomed all winter, and has spent the summer outside in the pot.  The calla is as large as the 15" square pot.  Can a calla get too big ??  Should I let it die down and try to separate the bulb some and if so, how do I let it die down (ie withhold water)?  Or is it ok taking up the entire pot? Thanks

Answer
The Calla specialist, Pacific Callas, actually posts a schedule of recommended container sizes for these popular plants:

http://www.callalilies.net/Potchart.htm

Their advice is based on the fact that restricted Calla roots cannot grow vigorously.  A 15 inch pot is PROBABLY more than large enough for the 'other' Calla, C. Aethiopica.  But don't take my word for it.  Remove the plant and have a look at the roots. If they fill the container, they're potbound and need more room.