Pachycereus marginatus

This handsome cactus has tall, columnar trunks and reaches heights of twenty feet, or more. It produces clusters of stout, cylindrical stems that resemble a pipe organ. The plant develops many arms during its lifetime and grows quicker with supplemental irrigation. It is deep green with ribs that have minor spines. Its central spine is yellowish and the smooth stems have five to seven ribs. The plant’s common name is derived from the fact that in many villages and towns of Mexico it is used to construct a living fence, mainly along roadways. In spring, the cactus produces tubular, pinkish-red flowers that are very showy. Following the bloom cycle, it develops spiny, yellowish to red fruit with black seeds. Plant the Mexican fencepost in well-draining soil and full sun with reflected heat or partial shade. It is drought-resistant, but likes occasional water during the hot, dry months. Let the soil completely dry out between irrigations. It is hardy to about twenty-five degrees Fahrenheit. Protect the tips of the plant when temperatures dip below the low twenties, by placing Styrofoam cups on the tips of the cactus. Use it as a desert accent or specimen; plant it against a tall wall, as a vertical accent, or create a living fence from cuttings of this plant. It also works well when used in desert or tropical settings and is relatively maintenance free. The Mexican fence post is native to the states of Hidalgo, Queretaro, and Guanajuato, and is widely planted and naturalized throughout Mexico.