The saguaro is probably the most famous cactus in the world. Almost everyone has heard about this majestic symbol of the desert.
 

Saguaros life: One saguaro produces tens of thousands of seeds in a year, and as many as 40 million in a lifetime of 175 to 200 years but out of all the seeds that a saguaro produces in a lifetime, few will survive to adulthood.

A saguaro's growth is extremely slow. After 15 years, the saguaro may be barely a foot tall. At about 30 years saguaros begin to flower and produce fruit. By 50 years the saguaro can be as tall as 2 m. After about 75 years on average, it may sprout its first branches, or "arms".  By 100 years the saguaro may have reached 7,5m. An adult saguaro is generally considered to be about 125 years of age. Saguaros that live 150 years Giant Saguaro or more attain the grandest sizes, towering as high as 15m or more and weighing 10 tons, sometimes more, dwarfing every other living thing in the desert. Saguaro rank among the largest of any cactus or desert plant in the world. The average life span of a saguaro is at least 150 - 175 years of age. However, biologists believe that some plants may live over 200 years.
One of the largest saguaros known to exist possessed these amazing stats: It lived 300 years, was over 12m tall, had 45 arms, and weighed 13 tons!
 

18 years old.

Photo and © copyright by Roberto González (Mexico)
Photo taken from the Federal Highway number 2, at 15 km from Sonora Sonoyta, Mexico (250 ms in front of the entrance to Santo Domingo), going in the direction of San Luis Río ( 31°55' 47" N and 112°59' 00" W)
The photo shows a strange shaped Sahuaro with distorted branches.  Sometimes when the gravity force is exerted on a branch in its most plastic stage, especially if it occurs in combination with drought, drooping will occur. New growth can take a new direction.

Photo of conspecific taxa, varieties, forms and cultivars of Lobivia (Echinopsis) pentlandii .
 of plants belonging to the Lobivia... complex (This Taxon has lots of synonyms (like most Lobivia) whit several controversial varieties and subspecies):

• Carnegia gigantea
• Carnegia gigantea cristata

Habitat: Sonoran Desert wherein the range is limited by freezing temperatures in winter. Saguaros are also limited by elevation. They are generally found growing on rocky slopes and well drained flats from nearly sea level to approximately 1100 m in elevation. Saguaros growing higher than 1100 m are usually found on south facing slopes where freezing temperatures are less likely to occur or are shorter in duration.

A young plant.

Propagation: From stem cuttings (if available) in spring (let them dry till the ends callous well. Then replant them in fresh cactus soil that is ever so slightly moist, and keep it that way till they root) or preferably by seeds (Seed should be sown in a well-drained soil mix. Surface sowing is the best; seeds germinate in 14-28 days at 20° C .

Culture: Saguaros grow very slowly and are cold intolerant, make sure that your saguaros are not exposed to freezing temperatures or they may die. Sun It need a well drained soil mix. Water regularly in summer but allow to dry fully before watering again. During the winter months they should be rather kept dry. Since they are big sized plants need plenty of space for their roots, repotting should be done every other year or when the plant has outgrown its pot. Exposure: Light shade when young, full sun later.