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How to Identify San Pedro Cactus

The San Pedro cactus (Trichocereus pachanoi) is native to the Andes, but is now common in the southwestern United States. It is usually grown for ornamental purposes; however, like the peyote catcus, the San Pedro cactus is also grown for the ingredient mescaline, a controlled substance with psychoactive effects if consumed. In many parts of the world, including the United States, it is legal to grow a San Pedro cactus but illegal to extract the mescaline and consume, trade or sell it. The San Pedro cactus is among the fastest growing cacti and can be identified from other cacti by a few distinguishing features.

Monitor its growth. A San Pedro cactus can grow up to a foot a year and can reach up to 20 feet tall and 6 feet wide.

Look at its shape. A San Pedro cactus is a tubular cactus that grows vertically, usually without arms. More than one stem can grow from the same crown.

  • The San Pedro cactus (Trichocereus pachanoi) is native to the Andes, but is now common in the southwestern United States.
  • The San Pedro cactus is among the fastest growing cacti and can be identified from other cacti by a few distinguishing features.

Count the ribs or columns that run vertically along the cactus. A San Pedro cactus has a total of 6 to 8 rounded ribs or columns with small spikes on top to keep away predators.

Observe its flowers, which bloom during the nighttime hours when it is cooler. San Pedro cacti grows white blooms, usually in July. They can grow to be nine inches in diameter.

Compare a picture of a San Pedro cactus with the cactus that is in question. Alternatively, take a picture of the cactus to your local nursery or county extension office for them to verify if it is a San Pedro cactus or not.

  • Count the ribs or columns that run vertically along the cactus.
  • A San Pedro cactus has a total of 6 to 8 rounded ribs or columns with small spikes on top to keep away predators.

San Pedro Cactus Be Grown From Seed?

San Pedro cacti bloom in midsummer, but their fruit doesn't fully ripen until early autumn. Remove the spongy matter from inside the fruit, then pick out the tiny black seeds. The right equipment and thorough preparation will substantially increase the likelihood of successfully germinating San Pedro cactus seeds because it will limit the chances of disease and infection. Fill the clean pots with the moistened medium, leaving the top 1/2 inch of each pot empty. San Pedro cactus seeds germinate somewhat erratically, so it is best to sow several in each pot. Six to eight hours of daily sunlight is also required, so position the pots near a south-facing window. Healthy San Pedro cactus seeds will germinate in roughly one month, at which point the seedlings should be thinned to one per pot and moved to a sheltered location outdoors.

  • San Pedro cacti bloom in midsummer, but their fruit doesn't fully ripen until early autumn.
  • Healthy San Pedro cactus seeds will germinate in roughly one month, at which point the seedlings should be thinned to one per pot and moved to a sheltered location outdoors.
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