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Mammillaria bocasana f. monstruosa

Botanical Name — Mammillaria bocasana f. monstruosa

Common Name — Fred

Plant Family — Cactaceae


Truly a Frankenstein’s monster of plants, Mammillaria bocasana f. Monstruosa, or Fred (named after the man who discovered it), is a nursery cultivated mutated clone of Mammillaria bocasana. There is very little family resemblance. It is famous for its rubbery green and pink globes, the occasional spike or hair out of nowhere, and its chaotic, tumorous growth habit that is always different from plant to plant. Every so often, an established plant will grow a branch that looks like the original Mammillaria bocasana, a mutation reversion, a small glimpse of what it once was...

Growth Requirements


  • These cacti prefer lots of filtered sun, at least five hours daily. Some full sun in the morning or late afternoon is fine, but Fred struggles in high heat peak sun. 
  • Indoors a southeast or southwest facing window is ideal. If you are growing this plant outdoors be sure to provide it with light shade to protect it from intense, peak afternoon sun.

Temperature/ Humidity 

  • Fred does best in high temperatures and low humidity. Ideal temperatures are above 65 ºF. These plants should be brought indoors when nighttime temperatures fall below 50 ºF.


  • Fred prefers to stay on the dry side. In the summer water only when the soil has dried out entirely. Always err on the side of underwatering. It is built to withstand drought, and overwatering is one of the quickest ways to kill Fred.
  • During the winter it’s safe to cut back on watering entirely. This will encourage flowering during the spring!


  • These plants require a gritty, sharply draining soil mix. Amend regular potting soil with sand or fine pumice up to 50% to improve drainage and soil texture. 


  • Fred rarely flowers, but if it does take on attributes of the original Mammillaria bocasana, it will produce a crown of pink flowers with yellow centers in spring and early summer. 


  • Fertilization of this plant is generally not necessary. If you want to refresh your soil or give your plant a boost during the growing season, you can feed it monthly with a fertilizer for cacti and succulents. Fertilize only during the spring and summer, when the  plant is actively growing.  


  • This plant can be propagated with stem cuttings. Allow cuttings to callous for several days before dusting with rooting hormone and placing in soil.



  • These plants are not especially susceptible to pests or diseases. Keep an eye out for pests that commonly affect houseplants, such as scale and mealybugs. Also look out for any unusual spotting that may be a sign of an infection. 
  • Treat infested plants with diluted neem oil. If plants are infected with a bacterial or fungal disease, prune away any affected parts of the plant. 
  • Root rot may occur if the plant gets too much water. If this happens, fear not! Cut away the mushy part of the plant and separate Fred into several smaller portions. Allow to callous and repot into separate pots. 

Maintenance (pruning, legginess, repotting)

  • Little maintenance is required to keep these plants happy. They should only need to be repotted once every two to three years. When transplanting, select a pot that is at least two to three inches wider in diameter to give the plant plenty of room to grow. 


  • This plant has no toxic effects reported. 
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