How to Care for a San Pedro Plant

Spread 1 inch of a light-colored gravel under the San Pedro cactus in a circular pattern and push it all the way up against the stem. Extend the gravel circle out from the base of the cactus plant at least 2 feet. This prevents water and soil from splashing up on the columns, which causes them to develop disease and to rot.

Water the soil under San Pedro cactus until it is completely saturated to a 5- or 6-inch depth. Afterward, allow the top 1 inch of soil to dry out completely before adding additional water. The cactus can withstand mild droughts and if rainfall occurs, additional watering is not required.

Spread a specialized cactus fertilizer, with numbers of 4-7-7 or 2-7-7, around the base of the San Pedro cactus in the early spring using the dosage requirements printed on the package. Repeat the fertilizer application once per month through the fall when the cactus stops growing.

Place potted San Pedro cactus plants in a location that maintains a temperature of between 41 and 50 degrees Fahrenheit in the winter months. The plant can withstand winter temperatures down to 15 degrees if planted outdoors.