Mammillaria karwinskiana is a small cactus native to southern Mexico. It is solitary or dichotomously branched to 5 inches (12 cm) in diameter and up to 8 inches (20 cm) tall. Tubercles are arranged spirally with 13-21 parastichys. Tufts of white hair are in between each tubercle and the spines are awl shaped, white tipped with brown up to 1.25 inches (3.3 cm) long. They easy to culture and make interesting specimens for any collection.
Blooming Time: In early spring. Small ¾ inch (2 cm) cream to yellow flowers adorn the crown of the plant.
Culture: Mammillaria karwinskiana need full sun to partial shade, with a well-drained soil mix. In the greenhouse, we use a soil mix consisting of 2 parts sand to 1 part loam with small gravel added to increase drainage. Plants are periodically well watered and then allowed to dry thoroughly before watering again. We fertilize plants once during per growing season using a balanced fertilizer diluted to ½ the strength recommended on the label. During the winter months, plants are grown at 50°F (10°C) and watered only enough to keep them from shriveling.
Propagation: Mammillaria karwinskiana is best propagated from seed. Seed readily germinates at 68°-72°F (20°-22°C).
Mammillaria karwinskiana was featured as Plant of the Week November 27-December 4, 2003.
Guide to Past Plants-of-the-Week:
Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2012 All rights reserved.