I have one other comment to add regarding this topic. If the pot is decorative with glazed surfaces (without and within) then I may use clay pots. They are more bulky, more difficult to repot from but the plant roots have no more reason than with plastic to head for the pot's walls. In this climate, even with everything exposed to the sun, bulbs as well as cacti and other succulent plants including bonsai, specimens do grow perfectly well in such pots. Except for the glazed requirement I use only impervious, plastic containers. These last up to five years, which is long enough before potting is required in any case. They provide, for me at any rate, one further advantage - the calcium in our water does not show up through the walls as it often does with unglazed clay. Andrew San Diego