City Trees is a premier publication focused on urban + community forestry. In each issue, you’ll learn how to best manage the trees in your community and more!
Issue link: http://read.dmtmag.com/i/75614
Transplanting Saguaro, Cactus Icon of the Southwest by Juan Barba, Arborist, Juan J. Barba & Associates, Tucson, Arizona Thoughts of Southwest deserts bring tree-sized cactus called saguaro (Carnegiea gigantea). Featured in many older western films, saguaros are native mainly in southern Arizona and across the bor- der in northern Mexico. Not only were they moved into other regions for movie sets, they have been moved into other states and countries as horticultural rarities. Rumors abound of saguaros sent for enormous sums to California, Las Vegas, and Japan. visions of sagebrush, sand, rattlesnakes, and that Saguaro is a large columnar cactus with arms develop- ing above ground. There are larger columnar cacti in the Americas, but saguaro is our only large native variety. Because of their size and desirability, saguaros have always been coveted and sometimes moved unlawfully and vandalized. Several decades ago, Arizona lawmak- ers attempted to protect them; now, specific authori- zations are needed to remove saguaros on State or federal lands. Saguaros on private property may, within the limits of certain native plant protection ordinances, be destroyed as needed. Property owners may remove them but are first required to notify the State and offer the saguaros to private, non-profit, or commercial salvage entities. Certain county and municipal entities have written plant protection ordinances that will often further protect saguaros in drainages, on private properties, and in developments. In these ordinances, mitigation plans are required before the saws or bulldozers start. Additionally, to protect saguaros from unscrupulous salvagers, a permit is needed to take or transport them from a growing site for salvaging or transplanting. Basically, it is not illegal to destroy them if notification is given, but it is necessary to purchase a permit to move them. Repairs to the original site, fines, or jail may be levied if saguaros are destroyed or moved illegally. Saguaro, the only specie in its genus, is very similar to other dicots in its root, flower, and fruit anatomy. Major differences from most dicots are seen in the cortex, vascular, and structural support tissues. The stems are coated in a thick cuticle under which a layer of chlo- rophyll-bearing cells resides. The fleshy portion of the trunk—usually 20 to 24 inches (51 to 61 cm) in diam- eter but at times much larger—is made of parenchyma and chlorenchyma cells providing moisture storage with similar turgor and texture to the moisture in a potato. The saguaro vascular system and structural support is within the "ribs," which are stiff, rod-like features 10 A saguaro cactus is prepared for transplanting. Photo Courtesy of Logan Simpson Design growing in a cylinder deep within the cactus. There is a single tap root; the rest of the roots are neither large in diameter nor are they very deep. They are not fibrous like grass roots but they spread widely and are likened to a spider web. They are close to the surface; most of the root system is only 4 inches (10 cm) deep. Like other arid plant roots, saguaro's are adept at capturing minute amounts of moisture. Care must be taken with the bigger roots, the soft fleshy trunk, and the poorly attached arms during transplanting. Transplanting success is high initially but low when the live ratio is counted five to ten years after moving. Saguaro movers consider it a success if the plant is alive for one to three years after moving, but the stored water and energy in one of these giants can make them appear to be fine for five years or more. Greatest suc- cess can be realized when these goals are attended to: move saguaros only under 7 feet (2.1 m) tall, capture the entire tap root, retain as much lateral root system as possible, plant at or near the original grade, and apply water to keep the cactus hydrated. There are saguaros all over the Phoenix and Tucson valleys that were moved while one or more of these five areas was defied—but that is not an indication of good horticulture, rather a testament to plant survival. City Trees