Question: I’d like information regarding ratio of pot size to plant.
Answer: This is probably the most frequently asked question in our shop. One of the most common mistakes the novice grower makes is to pot their violet into too large a pot, assuming that every repotting means potting into the next size pot. Having said that, it’s not true that an African violet needs to be “pot-bound”. What a violet needs, in fact what most houseplants need, is a pot just large enough to accommodate its root system. It is the size of the root system that determines pot size, not the size of the plant. The example we like to give is that of cactus. It may be larger than the person growing it, but its root system could fit nicely into a 8 or 10″ pot.
Generally speaking, most standard varieties, when grown as houseplants (not for exhibition), will do quite well in a 4″ pot. Most semiminiatures can be grown in pots no larger than 2 1/2″, and most miniatures in 2″ or 2 1/4″ pots. Since violets tend to be relatively shallow-rooted, azalea pots (pots slightly less deep than wide) are preferable. Unless you notice that the root system is crowded in its present pot, there’s no need to use a larger size. this would be the case if you noticed very dense root growth around the outside of the root ball when the plant is removed from its pot. No matter the size of the pot, violets normally should be repotted into fresh soil, at least twice a year. This will allow new roots to grow, keeping the root system, and therefore the plant, healthy.