Opuntia is the great survivor of the plant world, a genus of 145 species that has colonized everything from coastal dunes to high plains to suburban living rooms. Native to the Americas, it carries the padded, sculptural silhouette that defines our picture of the cactus — flat cladodes lined with spines up to 3 inches long, glochids that embed in skin at the lightest touch, and waxy flowers in orange, purple, red, or yellow that appear for a few brilliant weeks in late spring and early summer. The genus grows anywhere from 3 to 20 feet tall depending on species, and it will thrive in zones 3b through 11b so long as the soil drains freely and the sun is generous.

In the garden, Opuntia rewards minimal intervention. Plant it in sandy or rocky soil, water it through its first season to help establish the root system, then largely leave it alone. The pads break off easily and root themselves nearby, which is how a single plant becomes a colony over time — useful in erosion-prone dry borders, less desirable if the neighbors are close. The edible fruits (prickly pears) and pads (nopales) are harvested carefully with thick gloves; the reward is a subtle, watermelon-sweet flavor that has fed people across the Americas for thousands of years.