Growing Pincushion cactus, or mammillaria, is an easy gardening project for beginner and advanced gardeners alike. These drought-tolerant, compact, perennial plants make outstanding additions to succulent gardens or as standalone plants. Native to the hot and dry regions of the United States, Pincushion cactus are rounded, stubby plants that are covered in very prickly, white spines.
With the proper care and growing conditions, they will even produce some showy blooms. Follow our guide to growing Pincushion cactus so that you can avoid common mistakes and get the most out of these spiny, blooming treasures.
Where to Grow Mammillaria
The mammillaria plant is generally grown as an indoor succulent, but the plant can tolerate some cooler temperatures if it is grown outside.
Ideal Soil Composition for Growing Pincushion Cactus
Cactus plants are native to desert conditions and require sandy and well-draining soil. Plant Pincushion cactus plants in loose, rocky soil that is nutrient-rich for best results. If you are planting cactus in containers, use a potting mix specifically formulated for succulents and cacti and plant in a pot with holes in the bottom for drainage.
Mammillaria Cactus Light & Temperature Requirements
Provide your mammillaria cactus with intense and bright light from the sun for about four hours per day. Consider placing your cactus plant by a window that receives full morning sunlight and indirect sunlight for much of the day for optimal growth.
The ideal growing temperature for Pincushion Cacti is approximately 70°F. Aim to maintain temperatures in the range of 50°F and 75°F. Throughout the winter months, allow cactus plants to cool to encourage subsequent season flowering.
Keep cactus plants in areas where the air is dry and free from humidity. Avoid growing Pincushion cactus plants in kitchens and bathrooms where moisture levels are higher.
*Pro Tip: Once seeds germinate, remove them from the heat mat and place them underneath grow lights for best results.
- Poke a couple of holes in the bottom of some plastic cups.
- Fill cups with premoistened soil.
- Plant seeds in the soil.
- Tear off a piece of clear plastic wrap and place it over the top of each cup as a humidity dome.
- Place cups in a shallow tray.
- Remove plastic wraps from the cups as soon as you see that your seeds have sprouted.
When To Water a Pincushion Cactus
The Pincushion cactus plant enters into dormancy in the wintertime, and you can refrain from watering the plant until a couple of weeks into spring. Once spring arrives, Pincushion cactus plants should likely be watered approximately once a week. They need enough time to store the water and for the soil to dry out between watering.
Follow these tips and techniques for watering indoor succulent plants:
- Use a watering can with a small pour spout.
- Apply water to the core of the plant until it is fully saturated.
- Allow water to drain through the holes in the pot thoroughly. If there is a saucer underneath the plant, be sure to dump out any water that drains through the soil.
- Avoid saturating the leaves to ward off rot from the top-down since there will not be enough heat and fresh airflow to dry the plant when planted indoors.
- Allow soil to dry thoroughly between watering.
*Pro Tip: Potted cactus plants thrive well in unglazed clay pots, as they are porous and allow more airflow to plant root systems which keeps soil drier.
Fertilizing A Mammillaria Cactus
For optimal growth and successful bloom production, provide your pincushion cactus with fertilizer in springtime and every two weeks throughout the growing season. Use a fertilizer that is specifically formulated for cactus and succulent plants.
Growing Pincushion Cactus
Growing Mammillaria from Seed
- Start the plants from seed in spring.
- Moisten cactus and succulent mix evenly.
- Filled pot with cactus and succulent mix.
- Surface sow seeds and use a sifter to dust the seeds with more soil mix lightly.
- Place the containers in an area where the temperature is around 70 degrees Fahrenheit.
- Maintain even moisture levels and keep seeds saturated.
Propagating Pincushion Cactus Plants
When growing Pincushion cactus plants, they will produce offshoots when they mature. These small clusters can be divided from the mother plant to form new individual plants. Pincushion cactus plants can also be propagated from seed.
Growing Mammillaria from Offshoots
- Remove cactus offsets carefully from the mother plant.
- Dry the cut of the offsets on a paper towel for several days until it is callused.
- Once the callus forms, place the cutting into a pot filled with cactus and succulent mix.
- Place the container in a warm location in direct sunlight until new roots emerge.
*Pro Tip: If ideal temperature and watering environments are met, the pincushion cactus may reward you with flowers when springtime rolls in. Improve the chances of blooms by depriving water from the pincushion cacti until a few weeks into spring. Apply a cactus fertilizer in early spring to give the plant the boost of nutrients it requires for bloom production.
Recommended Mammillaria Varieties
Try growing pincushion cactus varieties like these and enjoy these long-lived, easy-going planting for many years to come. All of these varieties will produce flowers with the proper growing conditions.
- Crawling Log cactus: produce elongated stems.
- Snowball pincushion cactus: Rounded cactus head with white fuzz on the surface of the plant.
- Golden pincushion: Globe-shaped cactus with golden spines and longer central spines that have a wooly-looking surface.