Opuntia polycantha, or Prickly Pear, is a low spreading Opuntia native from North Dakota to Texas and Arizona. The joints are orbicular to 2-4 inches (5-10 cm) wide and long. Areoles are close set with 7-10 deflexed, cylindrical spines up to 0.75 inches (1.9 cm) long. Spines on the margins of joints will reach up to 1-2 inches (2.5-5 cm) long and are very sharp. These are very cold hardy cacti and will grow in the landscape in USDA zones 3-10.
Blooming: In the greenhouse, they bloom in late spring. Flowers are yellow to 3 inches (7.6 cm) across and are fairly showy.
Culture: Opuntia polycantha need full sun to light shade with a well drained soil mix. In the greenhouse, we use a soil mix consisting of equal parts of loam and sand with small gravel added to ensure good drainage. The plants are well watered and allowed to dry thoroughly before watering again. We fertilize them once during the growing season with a balanced fertilizer. The plants are extremely drought tolerant in the landscape. Since these are some of the cold hardiest of the cactuses, winter temps can drop pretty low and they will survive. In the greenhouse, we drop the winter temperatures to 48°F (9°C). During this period the plants are watered only enough to keep the pads from shriveling.
Propagation: Opuntia polycantha is propagated from cuttings and from seed.
Opuntia polycantha was featured as Plant of the Week April 18-24, 2008.
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 the late 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.