Native to Mexico
Cleistocactus strausii is a perennial cactus with is a slender, erect, columnar group-forming cactus, up to 10' tall and only about 2.5" in diameter, covered with so many silvery-white hairy spines that the green stem is almost completely hidden. It branch profusely from the base. The columns are formed from around 25 ribs and are densely covered with areoles, supporting four yellow-brown spines up to 2 inches long and 20 shorter white radials.
This plant is a heavy bloomer and mature cactuses, over 50 cm tall, will profusely produce deep violet-red tubular, slightly curved flowers. The blooms are 6 to 9 cm long and protrude horizontally from the stem on the sides near the tips. In common with other cacti in the genus Cleistocactus, the flowers hardly open, with only the style and stamens protruding. Floral tube with silky hairs.
Wooly Torch Cactus prefers bright light and ample airflow. Outside it likes full sun or afternoon shade, inside it needs bright light, and some direct sun. It requires excellent drainage provided by porous cactus soil. Repotting may be done every 2-3 years.
Water the soil abundantly when it is dry to the touch. Allow soil to drain thoroughly before watering again. Do not water much in the winter. Allow the soil mix to become nearly dry between waterings, but then water thoroughly. Suspend watering in the winter, but mist occasionally.
Fertilize Cleistocactus with a low-nitrogen fertilizer during the active growth period. A slow-release fertilizer applied in the spring will be sufficient for the whole year.
It is used as an ornamental, It is an excellent plant for container growing. It always looks good and stays small.