How Long Does a Cactus Last For?

Long-Lived Cacti

• Known to live 150 to 175 years, and probably to more than 200 years, the saguaro cactus of the Southwestern U.S. (Carnegiea gigantea), grow slowly for their early years, with a 1- to 1 1/2-inch-tall plant being 8 years old. Hardy in U.S. Department of Agriculture plant hardiness zones 9 and 10, mature saguaros reach 45 feet tall or more.

  Barrel cacti (Ferocactus spp.) can live up to 130 years. A golden barrel (Echinocactus grusonii) in California's Huntington Botanical Gardens is 85 years old. Barrel cacti grow in USDA zones 9 through 11.

  Surprisingly, the fragile-looking Christmas cactus (Schlumbergera truncata), hardy to USDA zones 10 through 12, may survive for more than 100 years as heirloom house plants.

Small But Old

• Some cacti, such as the living rock cacti (Ariocarpus spp.) of the Chihuahuan Desert, are suspected to be extremely long-lived even though the plants aren't massive. The flat plants have triangular tubercles and enlarged underground roots. A single-headed living rock cactus (Ariocarpus fissuratus) grown from seed blooms for the first time around 13 years old. A 36-year-old plant is about 5 inches wide; a 50-year-old plant is about 6 inches wide. With age they can become multiple-headed. It's thought that such plants are ancient, but several generations of botanists would have to study them to document their ages.

Shorter-Lived Cacti

• Generally, small, spherical cacti that never develop internal woody support tissue, such as crown cacti (Rebutia spp.) and chin cacti (Gymnocalycium spp.) are shorter-lived than columnar tree cacti or barrel cacti. Crown cactus is hardy in USDA zones 10 and 11, and chin cactus in zones 8 through 10. Prickly pears (Opuntia spp.), hardy in zones 3 through 11 depending on the species, are known to live more than 20 years. The grafted moon cactus (Gymnocalycium mihanovichii var. friedrichii) tends to be short-lived because it can't live on its own roots, and the commonest-used rootstock is susceptible to cold weather and to root rot.

Factors Affecting Longevity

• The cactus family is a large one, with more than 1,600 species and many cultivars. They grow in a wide variety of habitats, from tropical jungles to cold-winter Canadian prairies. To give your cacti the longest possible life, do research on them so you know their hardiness zones, what light conditions they prefer and if they need a dormant period. All cacti need well-draining potting mixes or soils. You can kill your plant by exposing it to cold weather, putting it in full sun suddenly or keeping the soil constantly wet, when in actuality it could live long enough to give to your grandchild.