The Thimble Cactus ‘Mammillaria Vetula’

The Thimble Cactus 'Mammillaria Vetula'

Also commonly known as “Thimble Cactus” or “Powder Tassel,” this is a low-maintenance, tussock cactus that does not usually exceed 3 inches in height, and grows in clusters has dark green conical tubers. The areolas have white wool and are round; these can include up to 50 intertwined radial white spines and 1 to 7 thicker central reddish spines. Some varieties of this plant are better known; they are smaller and have white central spines with a brown tip, with fewer radial spines, partly brown, and without central spines. These unique cacti are short in height, but they add a peculiar beauty and color to our garden because they grow in groups.


The ASPCA considers categorizes this plant as being non-toxic. This means that the plant is ideal for people with children and pets. You can place it indoors without having to worry about their safety.

Thimble Cactus-SC
A picture of Thimble Cactus @thedangergarden


Due to their small dimensions, the most common is to grow them in pots and planters. These are slow-growing, fast-spreading plants and are an excellent addition to rock and cactus gardens. Since it grows in clusters, it is also well suited to fairy gardens. Flowering in this species does not occur until the specimen is not at least three years old. The fruit is orange. It has small yellow or cream flowers.

While the usual flowering time for these succulents is late spring or early summer, in some cases, we can see beautiful and striking yellow flowers in winter as well. For this flowering to be best, allow the plants to enjoy a cooling period in winter. We must stop irrigation entirely during this time. One of the many characteristics that differentiate this cactus from others is that Mammillaria has tubers from which the flowers emerge at the time of flowering.

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Soil Required

Thimble Cactus requires porous soil; a particular substrate for cacti may be ideal. It can also grow well in a mixture of cactus soil and rich, fast-draining ordinary soil with a pH range between 6.1 and 6.5. Some species of these types of plants require sandier soil for potting cacti or succulents for best results. When grown in a pot, the earth can be a mixture, in equal parts, of coarse sand, garden soil, and leaf mulch or also a commercial substrate for cacti.

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In indoor cultivation, it produces a group of small round offsets around the mother plant. These are densely covered with silky white hair, and the body of the plant is generally green/blue. Since short white spines densely cover the globes, this looks like a speck of dust around the mother plant. If this cactus is kept in the right conditions, it grows slowly but steadily until it reaches its mature size. A slow-growing, mature Mammillaria cactus can grow to about 5 inches tall and 4 inches in diameter. To obtain the best results in its growth, provide the plants with good airflow; for this, we will find that a window sill with lots of sunlight is an optimal environment conducive to the cactus to thrive.

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Sunshine Bloom:IG@iowasian

Weather Conditions

The Mammillaria Gracilis cactus prefers full sun exposure; however, we must bear in mind that although most Mammillaria species prefer intense light, some cannot survive more than four hours of direct sunlight. It is also preferable to keep it in high temperatures. This little cactus grows well in temperatures between 70 and 80 ° F and becomes dormant in winter.

When temperatures drop to between 60 ° and 65 ° F, the plant will give flowers. The winter temperature should not drop below 41ºF, and although they could withstand a weak frost; It is convenient to rest at about 50ºF. Thanks to the fact that this cactus can withstand the cold well as long as it is dry, we can keep our “Thimble Cactus” as indoor plants during the winter. When summer returns, we can move our cactus outside again to receive more light and air and begin its spring flowering season. Since “Thimble Cactus” plants are not resistant to intense cold, we must offer them plenty of sun on a window sill protected from the elements.

thimble cactus in a clay pot
Source: IG@jaguarinthejungle


The watering of our “Thimble Cactus” will depend on the season in which we are. In summer we can water it regularly every other day, in spring, only about twice a week. In this measure, they will decrease in autumn until almost eliminating all irrigation in winter, this being approximately one time a month at most if they are grown outdoors. Something essential for this cactus’ healthy watering is to wait until the soil has completely dried before watering again to avoid drowning it. We must not expose our plant to prolonged humidity or let it rest in the water for extended periods, so we must be attentive to any dish under the pots to avoid any waterlogging.

Thimble Cactus-Fertilizers- potted in beautiful marble pots-SC
Source: IG@peacockandcompany


The “Thimble cactus” does not require specific pruning or fertilizer for its growth. However, we can fertilize it with commercial cactus compost in its growing periods to grow more healthily, and its flowering season is abundant. The pot transplant is carried out at the beginning of spring. Its cleaning and maintenance are simple. We must monitor any rot that appears and cut it quickly before it spreads. In case the plant is overcrowded, a pot transplant is necessary; this is an excellent opportunity to remove all the rotten or dead roots that our plant may have.

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It is possible to multiply our “Thimble Cactus” by rooting the lateral suckers or seeds sown in spring in a sandy and slightly humid substrate. To reproduce it by cutting, we must carefully remove the suckers and dry them for a couple of days. We will know that they will be ready to plant when a callus forms on the cut surface. At that time, we take a new pot filled with a mixture of substrate for cacti and garden soil; and there we will place our cuttings. It is imperative to keep them in a warm and dry place where they receive enough light.


Offsets are the easiest way to propagate this plant. The offset already has roots, and they are already little plants. The following is how to propagate by offsets.

  1. Remove the plant from the pot gently and remove the substrate from the roots to expose the offsets.
  2. Use a sterilized, sharp cutting tool to disconnect the offsets from the main plant.
  3. Allow the disconnected offset to be callous for two to three days.
  4. Plant the offset in a different pot with a suitable substrate for the thimble cactus.

Potting & Repotting

Having its natural habitat as generally hot and dry, it’s advisable to repot during the warm seasons. During winter, the plants tend to be dormant; thus when you repot it then, the plant may not be able to recover. Spring of pearls has very delicate shallow roots, you can repot the plant when the plant has matured and is well established.

If your plant has overgrown its current pot and you are looking for a pot to repot it, go for the next available size. A huge pot would not be a good idea as it would mean more soil than is necessary, leading to more water being retained. The increased moisture in the soil will cause the roots to rot, and eventually, the plant will die.

As with other succulents, the substrate for potting needs to be porous and well-draining to allow a good flow of water and air. A regular cactus mix available in local stores would work. You could also make your mix by adding grit and perlite to loamy soil. Take two portions of your soil and add a portion each of grit and perlite. Grit and perlite will make your soil more porous.

Well-draining soil is vital when growing this plant to avoid soil that allows water to stagnate as too much moisture causes root rot.

When re-potting your plant, you will need the below items

  • A bigger pot with drainage holes
  • Fresh porous substrate
  • Sterilized cutting tool
  • Water

Follow the below steps when you are re-potting:

  1. Prepare your pot by putting soil about halfway
  2. Slide the plant from its old pot carefully so you don’t damage its roots and leaves.
  3. Shake off old soil from the plant.
  4. Using your sterilized cutting tool, trim any dead roots and unhealthy stems.
  5. Place the plant in the new pot and fill it with the remaining soil.
  6. Water the plant adequately.
  7. Place the plant outside under a partial shade or inside near a window where it can access adequate light.

Pests And Diseases

These plants are susceptible to excess moisture; this produces rot in the roots that can spread to the stems and kill them. In case of excessive dryness, you will also be in danger of a spider mite attack. Growing as a houseplant often contracts bacterial diseases caused by excessive watering. That is why it is essential to follow a strict irrigation schedule. The “Thimble Cactus” is also susceptible to attack by some pests, such as mosquitoes or mites, but nothing is not resolved with insecticide or rubbing alcohol carefully.

Final Word

This beautiful plant is relatively easy to take care of. The main thing is to ensure the pottage is well drained and that you are watering it sparingly to keep its roots from rotting.

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Richard Miller

Salute everyone. It's Richard, the author of this Succulent & Xeriscaping blog. I am a traveler and a nature lover looking for a connection with the wild green. In my journey, I found a love for succulents and xeriscaping. What attracts me is the long-lasting & unique beauty of every plant I have the chance to see with my own eyes. Welcome to my little blog and let's enjoy a good time together!

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