Mammillaria mammillaris H.Karst.
Woolly Nipple Cactus
Cactus mammillaris, Cactus mammillaris var. glaber, Cactus mammillaris var. lanuginosus, Cactus mammillaris var. prolifer, Mammillaria caracassana, Mammillaria fuliginosa, Mammillaria pseudosimplex, Mammillaria simplex, Neomammillaria mammillaris
Mammillaria mammillaris is a solitary or clump-forming cactus with spherical to short cylindrical stems with conical tubercles, some white wool in the axils, and clusters of spines at the tips of each tubercle. The stems grow up to 4 inches (20 cm) in diameter. Spine clusters have 3 to 5 reddish-brown central spines with dark tips and 10 to 16 reddish-brown radial spines that become gray with age. The spines are up to 0.3 inches (0.8 cm) long. Flowers are funnel-shaped, up to 0.5 inches (1.3 cm) long, white to creamy-white, and emerge from the axils of tubercles in summer. Edible fruits are red, club-shaped, up to 0.8 inches (2 cm) long, and provide long-lasting ornament to the stems.
The specific epithet "mammillaris" derives from the Latin word "mammilla," meaning "nipple or teat" and the Latin suffix "-aris," and refers to the characteristic tubercles.
How to Grow and Care for Mammillaria mammillaris
Light: Plant this cactus in an area of your garden that receives 4 hours of direct sunlight a day. If you are growing M. mammillaris indoors, place it near the brightest window in your home or office to ensure your cactus gets enough light. If possible, place the pot on the balcony or in the garden for extra light from spring to fall.
Soil: M. mammillaris requires a soil mix that provides root aeration and good drainage, whether grown outdoors or indoors. Use commercial cactus potting mixes or create your own potting mix.
Hardiness: This cactus is heat tolerant, but it is not a cold-hardy plant. M. mammillaris can withstand temperatures as low as 30 to 50 °F (-1.1 to 10 °C), USDA hardiness zones 10a to 11b.
Watering: From spring to fall, water deeply and wait for the soil to dry out before watering again. Never let the pot sit in water. Suspend watering in the winter.
Fertilizing: M. mammillaris can benefit from fertilization during the growing season. Apply a water-soluble fertilizer for cacti and other succulents. Suspend feeding during the winter when the plant goes dormant.
Repotting: Repot every two or three years into a slightly larger pot. The best time to repot your M. mammillaris is late winter or early spring, but the repotting process can be done almost any time of the year.
Propagation: There are two easy ways to propagate M. mammillaris: by seeds or by dividing offsets. The best time to remove offsets is in spring and summer. Sow the seeds in late spring or summer.
Learn more at How to Grow and Care for Mammillaria.
Toxicity of Mammillaria mammillaris
M. mammillaris is considered non-toxic to both humans and pets.
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