World Plants

Cleistocactus strausii (Silver Torch, Wooly Torch)

USDA Hardiness Zone	10b
USDA Hardiness Ref.
Canadian Hardiness Zone	Requires cool season protection under glass.
Canada Hardiness Ref.
RHS Hardiness Zone	H2
RHS Hardiness Ref.
Temperature (°C)	1 - 5
Temperature (°F)	15
Height	3 m
Spread	6 - 8 cm
Growth	Slow
Flowering Period	August

General Description	Erect columnar cacti.
ID Characteristic	Evenly branched stems covered in white spines. Tubular red flowers scattered along the stems.
Shape	Cylindrical stems.
Landscape	Patio and container plants.
Propagation	By seed or stem cuttings.
Cultivation	Requires full sun in well drained soil but prefers plenty of water during the growing season. It can tolerate temperatures as low as -10°C in winter however it is intolerant of hot summer temperatures.
Pests	Prone to root rot if overwatered during its dormant period.
Notable Specimens	The University of Alberta Botanic Garden, Devon, Alberta, Canada.
Habitat	Found in higher elevations (3000 m) in the mountains of Argentina and Bolivia.
Flower Description	On older plants (above 50 cm in height) 6 cm long tubular, orange flowers are produced horizontally from the stems. Only the style and stamens protrude from the barely open flowers. Cultivated plants typically flower quite freely.