In the Sonoran Desert, you spot a 3-armed saguaro. Middle-aged? Ancient? Who can tell? Saguaro measure their time in decades, not in seasons. Here are some clues as to how old they is. Hint: If you look closely, the first few is easy to miss. (The plant hides out until it’s ready to show itself.) You can see life stages on the infographic above.
In its first several years, it’s hiding out under nurse plants; that’s why you don’t usually spot a tiny seedling, which may only reach an inch tall in a favorable wet year. Its strategy is to go slowly and wait until things has stabilized before rising up toward light. At 10 years old, the saguaro is hardly visible over shrubs. No wonder young ones are so elusive.
How to Tell How Old a Saguaro Is
Once it exits nurse plant’s shade, things really start growing. Around age thirty-five, it starts flowering. Another significant step. Reproductive maturity is the time for this plant to go from making vegetative growth (leaves) to making reproductive growth (flowers). Now it’s tall enough to carry flowers, feeding both doves and bats. At this point you may notice a six-foot column covered in blooms, but without any arms. No, not yet; arms comes along later (not early) in life. For three decades, it has been creating structure and getting itself high off the ground.
By the age of fifty to seventy, the first arm arises. At this point, the saguaro begins assuming its iconic profile, postcard-perfect. As you see in chart, single column gives way to something branched. Every arm increases the plant’s surface area, which means more seed and more flowers. This is an investment in next generation. A saguaro that’s a century old can reach up to thirty feet with several arms. It carries mark of each drought and monsoon season it has survived. Occasionally reaching two-hundred years old, saguaros will outlive us by a century or more. And when they do, they’re a big water tank. They act as a cushion against the harsh environment by holding tons of moisture within their thick trunks. Once tree dies, the ribs are all that’s left, growing in land for decades to come.
In contrast, other types of cactus grows fast, such as the cholla and hedgehog cacti, which take decades to reach maturity different than the saguaro. HOWEVER, you have to protect your cactus: Don’t carve on them, don’t climb on them; the cuts will invite rot. And again: the root zone. A saguaro will do better without competition in its immediate area, so keep the base clear of other plants and try to make sure it stays relatively dry. And if you stumble across a young one, like this, let it be. Let it have the nurse plant, not you.
Slow growth is necessary for survival, as age chart explains, because every inch uses up limited resources. To figure out the age of a saguaro, look at its height and arms. Maybe it’s a teenager, who just began blooming? Or maybe it is an old-timer, already a century old? The saguaro is a visible marker in the timekeeping of the desert; it keeps its own time, and when you understand that time you change your view of the landscape. You see the plants not as parts of a whole, but each one with its individual history.
To grow a saguaro takes patience. A helpful lesson in itself. We hurry through life, but they takes their time. It would of been better to wait. Saguaro dissapears into the horizon naturaly.