Mammillaria Bombycina “Silken Pincushion” Care & Buying Guide


Light requirementsHigh
Water requirementsLow
Ease of careEasy
Zone9a to 11b
Temperature resistanceMildly frost-hardy
Growth speedMedium
Indoor growingSuitable


Taking Care Of Mammillaria Bombycina “Silken Pincushion”

Ideal conditions

Like many cacti, Mammillaria Bombycina “Silken Pincushion” thrives outdoors due to its high light needs. Outdoors is where access to sunlight is the easiest for the cactus.

Growing the Silken Pincushion cactus indoors is possible as well. But if you want this cactus to get big, then indoor growing may not be optimal for it – growing up to around a foot tall and 3 feet wide, this cactus will occupy a lot of space when mature.

In terms of temperatures, the Silken Pincushion cactus is fairly frost-hardy (down to 20 degrees F/-6.7 degrees Celsius), but prolonged exposure to low temperature is undesirable.


Only water your Silken Pincushion cactus when its soil is dry to the touch. This cactus is drought-resistant and doesn’t require much water, and it also develops root rot if overwatered.

In winter, suspend watering since the cactus will be dormant and will require much less water than in summer.

Where to plant

Plant your Mammillaria Bombycina “Silken Pincushion” in fast-draining cactus soil. To encourage drainage further, add perlite, pumice, or coarse sand to the mix in a 1:1 ratio.

If you want to allow this cactus to grow big, then planting in garden soil will be optimal for it since the cactus won’t be restricted by any pots. However, this option is reasonable only if winters are warm in your area since otherwise, you will have to pot the cactus and bring it indoors.

Mammillaria Bombycina “Silken Pincushion” prefers partial to full sun, which makes outdoor growing ideal for it. If you want to grow it indoors though, it’s still possible – just make sure to place the pot with the cactus on a sunny window sill.

On very hot days or during heatwaves, you should temporarily move the cactus to a shaded location to protect it from sunburn.

General care information

For optimal growth, fertilize your Mammillaria Bombycina “Silken Pincushion” throughout spring and summer with a cactus fertilizer diluted to half strength. Depending on your fertilizer mix, fertilize your cactus once every 4 to 8 weeks.

Another thing you’ll have to do for good growth is repotting. 

You may repot your Silken Pincushion cactus only when it has outgrown its pot, which will probably happen every year or two.  But keep in mind that annual repotting allows you to inspect the roots of the plant and treat/remove damaged parts. Besides, introducing the cactus to fresh soil full of nutrients may boost the plant’s growth.

Before repotting your Mammillaria Bombycina “Silken Pincushion”, be sure to allow the soil to dry – this will make removal easier. Once the cactus is out, knock soil away off the roots, remove rotted or dead roots, and treat cuts with a fungicide. After placing the cactus in its new pot, leave the plant dry for around a week and then begin to lightly water it.