General advice about pots

I have recently been affected by the cacti 'bug' and have been building my collection very slowly. I do have several mammillarias but confess to being attracted to any pretty flowered cactus. I have a lot of questions to ask but will restrict my first post to just one query.
I have been very busy reading all about the conditions for keeping my cacti happy and the advice I get is to use terracotta pots. On browsing all the expert sites (which is where I found out about this forum) I discover that 99% of the cacti I have seen have been in plastic pots. Can anyone tell me which type of pot is best, or is this not critical for the growing conditions.
Liz

Hello Liz, and welcome to the Mammillaria Forum. For the record, you are our 200th member!

Now to try to answer your question. AS always, I am going to say it depends. But on what?

There are thre eor four factors, I believe - compost; pots; watering; and where you keep them.

Basically cacti like to drink water for very short periods, so you don't want to have them in wet soil for any longer than you can.

Most cacti like a very porous soil, with lots of grit, to let the water drain through quickly. I don't know your home country, but in the UK where I am from, we have a compost callled John Innes. I use 30% of the No 2 grade, 30% horticultural grit and 30% of something called Terramol - it is a sort of small particle baked clay which I get from bonsai growers. Some use a type of cat litter which is actually very simlar.

Terracotta pots will dry out more quickly than plastic pots. Some people swear by them, but for others it makes watering more difficult and onerous. Personally I use plastic pots, as they don't let the compost dry out quite so quickly, and so I don't have to water quite as often as when (many years ago now) I used terracotta.

Watering appears to vary - some stand their pots in water until all the compost is wet, and then leave to drain. Others (like me) water each pot from the top, using a watering can to pour the water around the plant until water starts to come out of the bottom of the pot, and then leave to drain. Others just get the hose pipe out and water that way!

It also depends on where you keep your plants and how hot it gets where they are. I have a greenhouse, and use plastic pots, a porous compost and water about every 3 weeks in the growing season, which is between April and end September here in the UK. Then no water for most species until the next March or April, a bit variable depending on the weather, and a 6C temperature.

So no straight answer, as I know many growers who use terracotta and hate using plastic pots.

But if you do use plastic, buy good ones, which don't get too fragile if exposed to the sun for a long time.

Please ask more if this is too indefinite an answer.

Hello Chris
Thank you for your response. I am - like you - in the UK. I'm not sure if I am using the forum correctly or whether I should just go through the FAQ to see if I can find my answers - I am very new to this and I do have lots of questions (sorry). I will just restrict them to one at a time though.
My next question is about the naming of cacti. I get rather confused about the fact that some seem to have synonyms that make looking them up very interesting e.g. I have a cactus called
Escobaria minima syn. Coryphantha nellieae. This is not a problem but I'm just curious as to why that is the case. Can anyone explain this to me please?

The naming of plants is not a simple matter either. The name of a plant is usually given by its genus and its species name. That sounds easy. But unfortunately there is no universal agreement on what defines a genus and certainly not on what defines a species. Work has been done to sort this out, which has resulted in groups of professional botanists and informed enthusiasts getting together to form an agreement. The result of that is a big two volume set called the New Cactus Lexicon.
Of course there are still those who disagree with these results, and to be honest, because of further research, especially DNA research, it is still a developing subject.
But coming back to your specific question, Coryphantha, I think, was erected as a genus first, and a number of species designated. Later on, botanists felt that there were certain characteristics of some species that were common to those species only and were significant enough to designate a new genus, and so Escobaria was erected (which means pubished in a scientific journal).
Sometimes genera which are split off - and a German botanist, Backeberg, did a lot of splitting of existing genera in the 1950's mainly - are later recombined, as the views of the botanists change.

Don't worry about asking questions, there are others besides me who answer them, and this all helps to add to what's on the forum.