It depends partly on your potting mix. I use the Gritty Mix that is popular in the Container Gardening forum for mature clivias. It is very heavy, and it drains fast. I use plastic pots for most of my mature clivias using that mix. For younger or smaller clivias, I prefer clay because it dries out a little faster and there is less risk of soggy soil and root rot. The discussion I link to below has changed the way I care my clivias and greatly improved my results. The potting mix you choose makes the biggest impact on your success.

Here is a link that might be useful: Container Soils -- Water Movement and Retention

This post was edited by Ohiofem on Wed, Mar 27, 13 at 1:03

I have a mix which is roughly 50/50 Perlite and peat. It seems to drain well c my other plants. I was thinking of repotting it into a clay pot. Should I add sand to my mix, or is that a good combination?