Saving the Giant Saguaro by Gerald D. A. Mueller, M.M.C
Copyrights (2000)
March through May is nesting time in the Phoenix Mountain Preserve, and the park is full of blooming cacti. It is also full of thousands of hikers, bicyclists, and tourists. Many visitors come to see the majestic Saguaro cactus in bloom. Others come to destroy it. (At Right: Nesting Great Horned Owl)
In his magazine, All About Saguaros, Carl Hodge said the Saguaro doesn't begin to produce its first seeds until it is 30 years old. But, in its lifetime, the Saguaro can produce up to 40 million seeds. However, out of those 40 million, only one is expected to reach full maturity.
Out in the desert, the Saguaro requires a minimum temperature of 70 degrees and at least two heavy rainfalls within five days for its seeds to germinate. When optimum moisture and temperature coincide, germination takes place in two-to-five days. Even then, each emerging Saguaro infant must have an umbrella—a rock or nurse plant—which shades it from the hot sun. In some cases, it might take as long as twenty years for a seed to germinate. Less than one single seed out of 1000 seeds lasts long enough to sprout.
That one, which does live to maturity, has the potential of growing into a natural phenomenon weighing 10 tons and reaching more than 50 feet into the air.
The Guinness Book of World Records (1989) calls a 57 foot-11 inch Saguaro southwest of Phoenix "The Tallest Cactus."
The Saguaro National Monument has a Saguaro known as the "Granddaddy of all Saguaros." The giant has 50 arms and is more than 40 feet tall. It is estimated more than 300 years old.
The Saguaro is also called the "Sentinel of the Desert." Undisturbed, its life will naturally span more than two hundred years. From the time the seed is germinated until it reaches its final stages—when all the spines wither away to dust—it will have reached a five-hundred year succession of life. To put that into perspective, Christopher Columbus discovered America more than 500 years ago in 1492.
During May, the majestic Saguaro starts to bud. It's called the "Miracle at Dusk." Each bud opens only once to be pollinated then closes and never opens again. Once pollinated, the Saguaro begins to produce its fruit—red pears. A late winter frost will doom any chance of pollination. (At Right - Six weeks later, three Great Horned Owl Nesting Fledglings)
This great sentinal seems to watch over the desert. It is considered a keystone species because it provides food and shelter for more than 100,000 desert dwellers— from birds of prey that nest high off the ground in its arms—to the multiple thousands of insects that feed off its fallen fruit.
For centuries, the Saguaro has given the Native American fruit, seed and drink. The natives harvested the fruit with long poles made from the spines of the Saguaro. Once the ripened fruit is dislodged, it gets processed into wine and jelly.
Scientists call this cactus an "Indicator Species" because they learn about the overall health of the desert by studying the Saguaro.
The Saguaro Cactus Boot - Often the Saguaro's arms are riddled with holes carved out by Gila Woodpeckers. The nest inside is called the boot because it is shaped like a man's foot. First, the mother bird pecks her way into the side of the plant, then down where she lays her eggs. (At Right - Woodpecker hole)
The Woodpecker is called the "Architect of the Boot." When she pecks away at the cactus, the Saguaro secretes a chemical compound that dries into a cork-like callus which seals off the cactus from further harm. The Woodpecker leaves and returns to lay her eggs when the chemical compound dries. Amazingly the durable callus boot lingers in tact on the ground years after the Saguaro itself succumbs to age, and even the spines have returned to dust. (At Right, a cactus boot found on desert floor)
An average life expectancy of a Saguaro in the wild is less than six weeks. Less than one percent lives longer, because any bug, rabbit, or even a cow, will eat the little bud for its moisture.
In a healthy desert, the Saguaro towers over its habitat. Its blossoms nurture the honey-bee. It feeds the dove, the bat and the rat. The coyote feeds on rabbits and baby quail that come to eat the sweet seeds. As insects forage on fallen fruit, the lizards eat them heartily.
Snakes keep shelter deep in the Saguaro's roots awaiting mice that seek shade from the hot sun. Snakes are known to have slithered up through the cactus needles and feed on nesting fledglings.
Among the many obstacles facing the Saguaro are (1) freezing and (2) lightning fires—which are the largest threat to the species. In 1994 over 1000 cacti were destroyed by fire in the Saguaro National Monument.
With the decrease in numbers of Saguaro, birds of prey seek alternative places to raise their nesting fledglings; and all too often, the nests get disturbed and the fledglings never reach maturity.
The desert's natural balance is losing ground to new housing communities. The Saguaro towers silently as new streets get built across its shade. It shares the air with the car, but the car doesn't reciprocate. It just drives in and Saguaros must get relocated or destroyed.
Theft and vandalism also exist—early in 1980; a hunter on an outing near Lake Pleasant fixed his shotgun point blank on one. The giant Saguaro collapsed killing both man and cactus instantly.
Furthermore, if man continues to press for laws that allow him to over-graze the desert and use the land for housing communities, the Saguaro will certainly face a fate of extinction.
The Saguaro National Monument was established in 1933 on the east side of Tucson to protect what was then one of the most inspiring stands of giant Saguaros found anywhere in the Sonoran Desert. Yet, even though the land that was set aside to protect the "Cactus Forest," only 52 years later—by 1985—the giant Saguaros had all but disappeared from the region—where thousands once stood like a regiment guarding a country.
When will the streets turn and go back to a place where a thousand forgotten years ago the Native American and Saguaros lived like brothers?
RELOCATING SAGUAROS
As stated, among the greatest obstacles facing the Saguaro are freezing and lightning fires. Relocating Saguaros into urban areas is one viable option for saving the Saguaro. However, the greatest threat within urban neighborhoods is over-watering. Remember, this specimen has survived for thousands of years without the aid of man's watering.
When relocating a Saguaro, take into mind that the cactus has a small root-ball and stabilizes its roots into hard earth which consists of sedimentary rock—a hardened deposit of calcium lime carbonate. The calcium carbonate cements together with other materials, including gravel, sand, clay and silt. This natural compound is found in aridisol and mollisol soil orders. It is called Caliche. Caliche is also known as "hardpan."
Caliche occurs worldwide, generally in arid or semiarid regions. The highest concentrations are in central and western Australia and in the high plains of the Western United States in the Sonoran Desert.
Recreating hardpan and developing a planting-well for relocating the Saguaro is paramount to lasting survival. A planting-well for the Saguaro should be about 3'-0" in length, by 3'-0" in width, by 3'-0" in depth maximum filled with three tiers of caliche, sand and rock mixtures.
The first tier in the planting-well should start with two inches of vitamin fortified sand at the bottom with a 10-inch layer of caliche mixed with pea sized gravel.
The second tier in the planting-well should start with two more inches fortified sand mixed with one-inch gravel, then a second 10-inch layer of caliche mixed with two-inch stone.
The top and final 12-inch tier should be a mixture of caliche mixed with baseball-to-football sized rock.The bottom of the root-ball should touch the top of the first tier—approximately 14 to 16 inches from the bottom of the planting-well. Four 3/4 inch PVC watering-tubes should be added into the corners of the planting-well for watering during the first three years. Make sure the tubes reach all the way to the bottom of the planting-well.
Stabilize the Saguaro with four or five 2x4s attached about 5 to 6 feet above ground at 35 to 45 degree angles. Make sure to protect the cactus with thick carpet at the contact points to protect the spines from damage caused by the 2x4 bracing.
When completely planted and the Saguaro is stabilized, moisten the entire planting-well with water (once) and tamp to create a solid base and let dry completely.
Fill the watering-tubes with vitamin fortified water once per week in summer months (only). This will encourage the roots to reach down and out toward the corners of the planting-well. Let natural rainfall do the remainder of the yearly watering. Discontinue watering after three years. The plant should then be finished with its transplant-shock cycle.