Matthew from the San Diego Reader gets the best questions.
How long do cactuses live? They always look like they’ve been there forever.
— Wayne, San Diego
Yep. They just sorta sit there, it seems. Most only grow a few inches a year. But since they don’t have growth rings like trees, and nobody’s hung around one cactus year after year to see how it goes, most estimates are educated guesses, pretty much. Short life span is maybe 25 years. But consider the saguaro. That’s the typical cartoon cactus with the robot arms and sometimes a Mexican peasant leaning against it. Those puppies apparently have convinced botanists they can live from 150 to 300 years. Maybe somebody found Cortez’s initials carved in one. Montezuma. Somebody like that. Anyway, all bets are off if the cactus is in a plastic pot on your desk. That probably has a life expectancy of six months, tops. Not because it dies, but because you get sick of it and throw it out.
And if you click the link, check out the question just before this one in the article.