Saguaro Cactus

When one thinks of desert cactus, Saguaro comes to mind. They are majestic in size and strangely shaped. They are only found in the Sonora Desert, part of which is in California and Arizona. Most of Baja California and the state of Sonora in Mexico is included. Saguaro do not tolerate frost so are found only below the elevation of 3500 feet.

Saguaro in Bloom

The arms of a Saguaro only grow after the cactus is 15 feet tall and has reached around 75 years of age. They can have many arms and average about 30 feet tall. The tallest are around 200 years old with more than 50 arms. They can grow to over 50 feet tall, but there are 50 varieties of tree like cacti in Mexico and So. America that are taller than Saguaro.

The skin of a Saguaro is smooth but inside are 2 inch spines that give a pleated look. As the cactus absorbs and stores water the pleats expand to store as much as a ton of water.
The many holes Gila Woodpeckers make digging for water are sealed by the plant to prevent water loss. The root system of a Saguaro is very shallow, radiating and wrapping around rocks for stability. The tap root is only about 3 feet long.

They bloom every year in May and June. Over a period of a month a few of the flowers open at night, secreting a sweet nectar. Bats, birds and insects help in pollination since Saguaro are only fertilized by another cactus. By noon the following day, the flower closes forever and if pollination has taken place a fruit will grow at the base of the flower. A ripe fruit will split when its 3 inches in size, scattering thousands of seeds.