A Saguaro's Growth Rate

A seed fallen on the dry desert floor will remain intact for numerous seasons. The heaviness of the sun's temperature will not be enough to crack it open. Nor will the strongest currents of a flash flood be enough to drown the seed. These currents can reposition the seed to an environment of protection or into a hungry bird's line of sight.

In the Protection of an Old Fence.

A protective environment, like in the shadow of a Palo Verde Tree and coupled with the humidity from a monsoon storm, the Saguaro seed will finally germinate. Its threadlike root arrangement can pull water molecules out of the driest of sand soils. Hidden in its world the Saguaro seedling begins to grow only one inch in its first year but in 15 years it will reach one foot in height.

Its slow growth rate presented a mathematical word problem to me. If a Saguaro Cactus takes 15 years to grow one foot, how many years will it take this same Saguaro to grow 30 feet tall? The answer would be 450 years, which in my thinking is not a slow growth rate at all in desert standards.

It is no secret that the longevity and slow growth rate of a spiny green whale is dependent on rain fall during a desert's cycle of monsoon storms. What most do not know is that a Saguaro's size can be further slowed in a dry season or seasons in which a Saguaro responds by shriveling and then turns to a yellow color. However, once the rain water returns, the Saguaro will revert to its healthier state. Such is their resilience to desert climate.

A monsoon storm is rich in rain water and rain water is the purest form of water. Pure water is a catalyst in a Saguaro's growth rate, so, could I apply this knowledge to somehow harvest the power of pure water? And then, channel this power to increase the growth rate of a home grown Saguaro seedling?  The potential for an immediate growth brought to mind a silly image of an 80 Foot Saguaro Cactus breaking through the floor and crashing into the ceiling of my home.

3 Weeks Old- Saguaro Seedlings.

I eventually discovered that in providing the Saguaro seedling with a regiment of weekly waterings of pure water, its growth rate can average 6 inches a year (as told by a professional Saguaro Cacti grower in Tucson, AZ). This estimates to 1 foot of upwards growth for every 2 years. This means that once a seedling has been planted in its proper soil, it can grow 30 feet high in 60 years.

Close to 2 years old.

I prefer this growth rate better, it allows for the possibility of me fully growing a giant Saguaro in my backyard. In a hundred years I may have to change this blog name from, 'Follow Me Through the Desert', to, 'Follow Me Through My Backyard' and take a closer look at the slow growing blessing of the desert. 

Saguaro Cacti Mathematics

I gazed into the sun washed landscape and my mental comparisons of the ocean to the desert engaged me in thought again (read post September 30, 2010).  I viewed deeply into the solid ocean to see two hundred spiny, green whales of the desert, planted in place. This population of motionless Saguaro Cacti standing in their rocky brush intrigued me; their numbers were deep.

It is no secret that a Saguaro Cactus standing up to 80 ft into the hot sky is first grown from a black seed. However, outside of the desert, most do not know a black Saguaro seed measures half the size of a single grain of sand. What else is rarely known about the Saguaro Cacti seed is that 2,500 are produced inside a 2 ounce Saguaro fruit or that a Saguaro Cactus can grow an average of 250,000 of these black seeds (or 100 fruits).

When I compared the 200 Saguaro Cacti with the 250,000 seeds a single Saguaro Cactus can produce, a mathematical conundrum became evident; why aren't more Saguaro Cacti inhabiting the desert landscape? This question prompted the term 'Saguaro Cacti Mathematics' to mind.

In Saguaro Cacti Mathematics, an interesting result occurs, only 1 out of 1,000 black seeds will sprout open in the harsh desert climate. That is 2 seedlings for every 1 Saguaro fruit (containing 2,500 seeds). The Saguaro Cacti Math continues, for every 500,000 seeds produced in the desert, only a 1cm short seedling will live and mature into a Giant Saguaro Cactus. Which in my thinking is not a bad success rate in desert standards.


The desert-wonders of seed propagation conjured inner creative imagery. Imagine the inner world of the Saguaro Cacti seed. Inside its microscopic core, swimming from its murky depths, the embryo of the spiny, green whale rises to the desert surface and sprouts into a seedling- while at the same time, the next seedlings out the next 500,000 await to make a journey of their own. 


I continued my gaze of the 200 Saguaro cacti and I took into consideration the life cycle each Saguaro will encounter. I endeavored to add myself into the Saguaro Cacti Equation. So I too planted 50 black seeds and was astounded to see 50 seedlings sprout. I like my success rate better! My next thought, can I live long enough to grow a seedling into an 80 foot giant? Follow me through the desert and share in my next thoughts. (see pictures below)

A Solid Ocean

     While driving from Northern California to Arizona, I compared the desert to the ocean. I once heard the ocean described as a liquid desert, so, I reasoned, could I describe the desert as a solid ocean?

     Even though most people, myself included, have never personally seen the inside of an ocean, it is no secret that an ocean contains various mountains and is also teaming with life. As I looked outside of my car, I saw dusty mountains which seem to stare back in silence. I also saw teams of Saguaro Cactuses living in the desert. 

     As we drove, each cactus-arm pointed upwards as if greeting me and my family. "Yes." I thought, "in desert terms there is life in the desert and the desert can be like an ocean and the giant Saguaro Cactus can be the desert's spiny, green whale".

     I believe most people have never personally seen a Saguaro Cactus in the desert, yet it is no secret that a Saguaro Cactus is the most recognized cactus of its species. However, to see a Saguaro Cactus as a half inch seedling, to me is a rare sight. I learned that a Saguaro seedling usually grows next to a Palo Verde Tree, or inside a desert bush and for that mater, within the cleft of rocks. In this way they are protected from direct sunlight and out of plain sight. Still rarer than that, is the spec of seed from which an 80 foot, 200 year old Saguaro Cactus is first propagated from. (view seedlings below.)

     Follow me through the desert and take a closer look at the Giant Saguaro, the green whale of the solid ocean.