Cleistocactus strausii – Silver Torch Cactus
Slender, erect, grey-green columns, with burgundy flowers in spring.
This cactus will grow up to 3M tall, though they are only some 6cm across. The flowers appear over a long period in spring, though only on mature plants. The flowers hardly open, with only the style and stamens protruding; giving its name as kleistos is Greek for “closed”. The woolly appearance is deeply misleading, as the columns are very spiky to the touch .
C. strausii is a perennial cacti endemic to Peru, Uruguay, Bolivia, and Argentina. It lives in high, mountainous regions, above 3,000M, that are dry and semi-arid. In temperate climates it is often grown under glass, and it does have the Award of Garden Merit from the UK Royal Horticultural Society.
Soil / Aspect:
It thrives in porous soil and full sun. Though it does not require full sun to survive it will not flower without it. C. strausii can withstand hard frosts, down to -10degC. The one thing it cannot stand is too much water in winter, which will lead to root rot.
The dead flower heads are a little unsightly and can easily be removed by hand. It is said to suffer from Mealy Bugs in the wild, though this has not been a problem in our garden. Propagation may be done by cutting away a young stem at the base – rather like a Yucca cutting, let it rest in a cool place out of direct sunlight for a couple of days, before planting or potting up, to encourage rooting.