How does living in the tropics alter cultivation?

[DaveW]

Cacti will virtually shut down and stop growing if nights are too warm since they are CAM (Crassulacean Acid Metabolism) plants, which unlike most plants do much of their photosynthesis at night therefore often go dormant in the height of summer.

A quote from the following link:-

"In order to be able to do the above two functions, many succulents have a special variant of photosynthesis called CAM. Without going into technical detail, CAM plants are ten times more efficient with water consumption than non-CAM plants. This is very important where water is scarce. It's important for growers to know that CAM requires a big day-night temperature differential to work, at least 15 degrees Fahrenheit."

http://www.tucsoncactus.org/html/growin ... _2011.html" onclick="window.open(this.href);return false;

A quote from the following link:-

"When conditions are extremely arid, CAM plants can just leave their stoma closed night and day, and the organic cycle is fed by internal recycling of the nocturnally fixed respiratory carbon dioxide. Of course, this is somewhat like a perpetual motion machine, and because there are costs in running this machinery, the plant cannot CAM-idle for very long. This idling does, however, allow the plants to survive dry spells and recover quickly when water is again available. This is quite unlike plants that drop their leaves and go dormant during dry spells."

http://www.hscactus.org/photosyn.html" onclick="window.open(this.href);return false;

Your plants therefore will go dormant themselves if conditions are too warm at night or dry for transpiration to continue.

[Steve Johnson]

It's only recently that it's easier to acquire the rarer/more desirable/exotic species here too, and I'm trying to get my hands on tropicals like Discocactus, Melocactus, Uebelmannia, etc. and see how easy or difficult they will be here

Not sure about Uebelmannia, but I think you should do quite well with Discocactus and Melocactus in your climate. Even here in fairly temperate L.A., nights can be chilly enough in winter to cause problems if they're left outdoors when the overnight lows go below 40F. Obviously you won't have that problem, and year-round growth for these genera is certainly possible.

[7george]

I heard many Mammillaria species don't do well in wet climate. Many cacti can be attacked by fungi in humid atmosphere. You should try growing those plants for some years to know this for sure. Do you have some blooming recently?