Pachycereus marginatus, commonly known as Mexican Fence Post Cactus, is an evergreen succulent native to the arid and semi-arid regions of Central Mexico. It is characterized by its columnar trunks that grow slowly to 12 feet (3.7 m) tall and may eventually reach up to 20 feet (6.1 m) in height. The stems are 3 to 4 inches (9–10 cm) in diameter, with 5 to 7 prominent ribs. The central spine is about 3/8 inch (1 cm) in diameter with five to nine radials and is slightly yellowish, which is less intimidating than the spines of more aggressive cacti species. This cactus is notable for its pink and red flowers that bloom in the spring, adding a splash of color to the landscape.

The Mexican Fence Post Cactus is valued for its vertical form and ease of maintenance, making it a popular choice for creating living fences in dry climates, as well as for use in xeriscaping and as a dramatic accent in succulent gardens. It thrives in full sun and requires minimal water, making it suitable for drought-tolerant landscapes. It prefers well-draining soils and is tolerant of poor soil conditions. While it is generally free of serious pests and diseases, root rot can occur if overwatered. It is also frost-sensitive and should be protected from freezing temperatures.CC BY-SA 4.0