Mexican Fence Post
Pachycereus marginatus. USDA zone 9a-11b, hardy to 25F. Lives: Front patio.
About this Mexican Fence Post
Pachycereus marginatus, the Mexican Fence Post cactus, is a columnar cactus native to the scrubby hillsides and dry valleys of central Mexico, from Hidalgo south through Oaxaca. In the wild it grows in dense, upright stands — often used by local communities as a living fence — reaching 15–20 feet with stems 4–6 inches in diameter. The dark green columns have 5–7 ribs lined with closely spaced white to gray areoles that form a nearly continuous ridge along each rib, giving the plant a clean, architectural look. In late spring it produces small, tubular pink to reddish flowers near the stem tips, opening at night and pollinated by bats. Unlike many columnar cacti, it offsets readily from the base, eventually forming a multi-stemmed clump.
Picked up at TLC Nursery in OKC on April 10th, 2026. The clean columnar form and the way the areoles line up in white ridges down each rib make this one of the more striking uprights you can grow in Oklahoma. It's going on the front patio where it should have plenty of room to start climbing.