If you’re looking for some small cactus for indoors as houseplants or outdoors in container gardens, the pin cushion cactus are worthy of attention.
Also known as warty cactus, these are members of the Mammillaria genus. There is any number of individual species. These are native to parts of North and South America, and Central America with quite a few of these being from Mexico.
Pin cushions are perfectly shaped miniatures that are mostly globular. However, they are sometimes more cylindrical.
The growth habit does depend upon the species. While some may have multiple round bodies that form clusters, others are solitary. In some cases, mature plants can form large clumps.
The pin cushions have several very attractive features. First, there are the tubercles that are arranged in a pleasing spiral fashion. As the name implies, the pin cushions will have either spines or bristles that typically can occur in neat clusters just like pins.
When in bloom, the pin cushion cacti are quite spectacular. Opening during the day, the bell-shaped, colorful flowers form rings around the crowns of the plants. They open from the joints of the tubercles. These open from the spring through the fall. Later, during the growing season, the body will be dotted with attractive glossy fruits that ripen to red.
These plants need a rest period during the winter months when watering should be reduced. They need a porous, coarse, well draining potting mix or garden soil.
The pin cushions are considered very easy to grow, and would be suitable for beginners.
There are numerous species, including the following.
Coral cactus (Mammillaria heyderi) has white blooms with tinges of pink or red.
Little candles (Mammillaria prolifera) is also known as silver cluster cactus. This has lovely yellow flowers.
Rose pin cushion (Mammillaria zeilmanniana) is noted for its bright purplish-pink flowers that form circles around the top of the plant. The blooms are so numerous that they form a mass around the plant. This species is popularly grown as a houseplant and pot plant.
Snowball cactus (Mammillaria bocasana) has yellow flowers. This is also known as powder puff.