How far apart should Prickly Pear Cactus be planted?

The seedlings should be planted at least ¾ inches/2 centimeters apart. Once they're ready to be planted in the ground, they need to be spaced to allow for their expected mature size. The adult size well may be less than expected. But the plants do better with adequate spacing. This way, their roots won't get intertwined, and the plants will have their own identifiable soil food web and moisture spheres upon which to draw for water, minerals, and dissolved nutrients.