Mammillaria Pilcayensis “Bristle Brush” Care & Buying Guide

Mammillaria Pilcayensis


Light requirementsHigh
Water requirementsLow
Ease of careEasy
Zone9b to 10b
Temperature resistanceNot frost-hardy
Growth speedMedium
Indoor growingSuitable


Taking Care Of Mammillaria Pilcayensis “Bristle Brush”

Ideal conditions

Reaching a height of up to 18-24 inches, Mammillaria Pilcayensis “Bristle Brush” should be kept outside. What also supports this is that the Bristle Brush cactus requires partial to full sun. This cactus also likes temperatures on the warmer end, and it shouldn’t be kept outdoors if winters are cold in your area.


Water the Bristle Brush only when its soil is dry to the touch – this cactus is drought-tolerant and requires not too much water. Avoid overwatering the Bristle Brush cactus since it may lead to waterlogging or root rot.

If keeping the cactus outdoors, keep track of the weather – if it’s rainy in your area, you may not need to water the cactus yourself. But if rains aren’t expected for some time, then keep an eye on the cactus soil and water if dry.

In winter, don’t water the Bristle Brush cactus – it will be dormant and won’t require as much water as in summer. Root rot is also much more likely in winter.

Where to plant

Plant the Bristle Brush cactus in light cactus soil that drains fast. You may also mix in some perlite or pumice in an around 1:1 ratio for increased drainage.

If keeping the cactus potted, choose a pot that has large drainage holes at the bottom.

Given the size of the Bristle Brush cactus, most people will probably find that keeping it outside is the most convenient for them. And as mentioned above, outdoor placement makes taking care of the cactus’ light needs very easy.

Though the Bristle Brush cactus requires partial to full sunlight, it should be kept in a shaded location on very hot days to prevent sunburn.

If keeping the cactus indoors, pick a location that is brightly lit all day. A window sill that receives direct sun would be the best option.

In winter, keep track of temperatures and move the plant inside if it gets too cold. The Bristle Brush cactus isn’t too cold-hardy, so you should take care to protect it from freezing.

General care information

The Bristle Brush cactus is a relatively fast grower, so it may do well without fertilization. But for best results, fertilize the cactus with a cactus fertilizer mix once every 4-8 weeks, depending on your solution and its strength.

Given that Bristle Brush cacti get pretty big, you will probably have to repot yours into a bigger pot several times throughout its lifetime. You may repot the cactus when you feel that it has outgrown its pot, but it may be a good idea to repot it every spring or summer.

Frequent repotting allows you to inspect the root structure of the plant and see how it’s doing. Besides, it’s believed that introducing the cactus to new soil boosts its growth.