Interesting Saguaro Cactus Facts

One of Arizona’s most majestic, lovable desert cactus plants is the Saguaro, Carnegiea gigantea. Being aware of the saguaro’s history and incredible internal design, it is an honor to walk close to the Giant Saguaro that is over 150 years old and standing tall.

Sonoran Desert cactus tall

Giant Saguaro Cactus of Arizona

These desert cacti are large, tree-like columnar cacti that develop branches (or arms) as they age.

Saguaro Cactus can not tolerate freezing temperatures in the winter and this is what limits their range.

Saguaro National Park

Saguaro Cactus

Saguaro FACTS:  Saguaros are a very slow growing cactus.  A 10 year old plant might only be 2 inches tall.

How tall can a Saguaro Cactus grow?  It can grow 40 to 60 feet tall.

Arizona Saguaro Giant Cactus

Saguaro Cactus on Mica Mountain

60 foot Saguaro Cactus plant

A Tall Saguaro Cactus

Below are Saguaro cacti at the bottom of Mica Mountain in Saguaro National Park.

Mica Mountain Saguaro National Park

Saguaro cactus roots are only 4-6 inches deep and travel out as far from the plant as it is tall. There is one deep tap root that extends down into the ground.

A Saguaro Cactus can gather enough water through its remarkable root system, during a significant rain, to last a year!

holes in big cactus

Holes in Saguaro Cactus for birds nest

Why are there holes in the Saguaro Cactus?  The gilded flicker and Gila woodpecker excavate nest cavities inside the saguaro’s pulpy flesh.

Birds nesting in the Arizona Saguaro Cactus

Cactus Wrens are common birds that live in the holes (nests) of the Saguaro Cactus.

red fruit of cactus

Saguaro Cactus Flowers bloom, then turn to fruit

When a saguaro reaches 35 years of age it begins to produce flowers.

white flower on cactus arizona

Saguaro cactus Bloom – Flower

A Saguaro can only be fertilized from a different cactus – cross pollination.  Only a few bloom each night awaiting to be pollinated and close by late morning.

pollinated cactus flower to fruit

red fruit on Saguaro Cactus

dead saguaro cactus ribs

A living and dead Saguaro Cactus.

Because the major part of a desert saguaro cactus is made up of water, an adult plant may weigh 6 tons or more. This tremendous weight is supported by a circular skeleton of inter-connected, woody ribs.

After the saguaro dies its wood ribs can be used to build roofs, fences, and parts of furniture.  The holes that birds nested in are called saguaro boots.

holes in cactus in Arizona

Saguaro Boot used by Native American

Native Americans used saguaro boots as water containers.

200 year old tall saguaro cactus

Saguaro Cactus next to a biker to compare the size

Saguaro branches normally begin to appear when the cactus reaches 50 to 70 years of age.

The average life span of a saguaro is approximately 175 years of age.  Experts have estimated that a Saguaro Cactus with more than 5 arms can be 200 years old.

nurse tree for saguaro cactus

Yellow Palo Verde Tree is a nurse tree

Young saguaro cacti can be very hard to find because they grow under the protection of a “nurse tree”.  The nurse tree releases nitrogen in the soil which the Saguaros and other desert cacti use to grow healthy and strong.

Saguaros sometimes grow in odd shapes or forms. The growing tip of the cactus occasionally produces a fan-like form which is referred to as crested or cristate.

rare arizona cactus

Cristate Saguaro Cactus

These crested saguaro cacti, Carnegia gigantea forma cristata, are rare.  Biologists are not sure why these Saguaros grow this fan-like shape.

Fan like shaped cactus rare

Crested, Cristate, Fan-like Saguaro Cactus from AZ

crested cristate cactus in Tucson Phoenix

rare Saguaro in Tucson

Arizona has strict regulations about the harvesting, collection or destruction of  The Arizona Saguaro Cactus. It is illegal to harm a Saguaro in Arizona. During building or construction, precautions must be taken to move every saguaro that may be affected.

The Saguaro cactus species in Arizona

Within Arizona’s Tucson Basin is The Saguaro National Park.  This park provides the ideal conditions for sustaining dense stands of the famous saguaro cactus.

saguaro cactus at The Saguaro National Park

saguaro cactus at The Saguaro National Park in Tucson

**The most important factors for growth are water and temperature. If the elevation is too high, the cold weather and frost can kill the saguaro. Although the Sonoran Desert experiences both winter and summer rains, studies show that the Saguaro cactus obtains most of its moisture during the summer monsoon season.

Saguaro National Park

saguaro cactus in Arizona

There are dozens of varieties of cacti;  short, tall, stout, delicate but none quite as magnificent as the Giant Saguaro cactus.

Quick Saguaro Facts:

  1. Saguaros have one deep tap-root but most of this cactus’ roots are 4-6 inches deep and span out as far as the desert plant is tall.
  2. The saguaro is the largest cactus in the US.
  3. After the saguaro dies its woody ribs can be used to build roofs, fences, and parts of furniture.
  4. The Giant Saguaro can live to be 200 years old.

In the Sonoran desert the saguaro cactus has a boundless variety of towering and many armed shapes.

the saguaro cactus in arizona

the saguaro cactus species in AZ

Water makes up 75 to 95 percent of the saguaro cactus’ weight.  During periods of drought the pleats of the saguaro cactus contract.  During Arizona rains the saguaro expands as it soaks up moisture.

saguaro cactus with fruit

saguaro cactus close up

Saguaros, like many desert cacti, grow excruciatingly slow.  Arizona cactus experts estimate that a forty-foot tall saguaro is about 150 years old.  Arm buds begin to appear when the saguaro is 75 years old.

the saguaro arms

the saguaro arm buds

Many saguaros now standing in cactus forests germinated in the mid-1800s.

saguaro cacti over 100 years old

saguaro cacti over 100 years old

To survive their early years, saguaro seedlings must be sheltered from the elements, whether it be under the canopy of other plants or in the crevices of rocky outcrops. Saguaro seeds can be deposited in droppings of birds roosting on branches of shrubs and trees.

nurse tree

young saguaro cacti under a nurse tree

Lightning, powerful winds, harsh winter freezes and the rotting of dead tissue kill saguaros.  The saguaro’s woody ribs stay on the desert floor until they are consumed by termites or decay and return to the soil.

dead saguaro cactus wood

woody spine of the dead saguaro cactus

The saguaro is not currently listed as threatened or endangered. Arizona has strict regulations about the harvesting, collection or destruction of the saguaro cactus.

dead saguaro cactus

dead saguaro cactus

Saguaro cactus can be found in southern Arizona and western Sonora, Mexico.

Related saguaro facts and photos:

http://tjsgarden.com/2012/06/23/saguaro-national-park-cactus-blooms-flowers/