• AGM plants

    AGM plants have been through a rigorous trial and assessment programme. They are:

    • Excellent for ordinary use in appropriate conditions
    • Available to buy
    • Of good constitution
    • Essentially stable in form & colour
    • Reasonably resistant to pests & diseases

Cleistocactus strausii

silver torch

AGM plants

AGM plants have been through a rigorous trial and assessment programme. They are:

  • Excellent for ordinary use in appropriate conditions
  • Available to buy
  • Of good constitution
  • Essentially stable in form & colour
  • Reasonably resistant to pests & diseases
silver torch

© � RHS 2003

  • Other common names silver torch
    silver torch cactus

  • Genus Cleistocactus are erect columnar cacti with ribbed, eventually branched, cylindrical stems bearing dense spines and tubular flowers

  • Family Cactaceae / Cactaceae

  • Details C. strausii grow to 1.5m, with branched erect stems densely covered with short white spines; tubular rose-red flowers 8cm in length are borne scattered along the stems in summer

  • Plant range S Bolivia

Characteristics

  • Foliage Evergreen

  • Habit Columnar/Upright

  • Hardiness

    Hardiness ratings

    All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

    • H1a - Under glass all year (>15C)
    • H1b - Can be grown outside in the summer (10 - 15)
    • H1c - Can be grown outside in the summer (5 - 10)
    • H2 - Tolerant of low temperatures, but not surviving being frozen (1 to 5)
    • H3 - Hardy in coastal and relatively mild parts of the UK (-5 to 1)
    • H4 - Hardy through most of the UK (-10 to -5)
    • H5 - Hardy in most places throughout the UK even in severe winters (-15 to -10)
    • H6 - Hardy in all of UK and northern Europe (-20 to -15)
    • H7 - Hardy in the severest European continental climates (< -20)
    Old hardiness ratings

    While we update our systems with the new hardiness ratings you may still see old hardiness ratings in your search results. These are denoted as 'Old'.

    • H1 - Requires heated glass
    • H2 - Requires unheated glass
    • H3 - Hardy outside in some regions of the UK
    • H4 - Hardy throughout the UK
    • H1 + H3 - Requires heated glass but may be grown outside in summer

    For full details of the hardiness ratings see

    see more

    H2

Colour

Sunlight

  • Full Sun

  • Aspect North-facing or East-facing or West-facing

  • Exposure Sheltered

Soil

  • Chalk

    Sand

  • Chalk

    Loam

  • MoistureWell-drained

  • SoilSand, Loam

  • pHAcid, Neutral, Alkaline

Size

  • Ultimate height

    1-1.5 metres

  • Ultimate spread

    0.5-1 metres

  • Time to ultimate height

    5-10 years

How to grow

Cultivation Grow under glass in a standard cactus compost, in full light. Provide low humidity. Water freely when in growth and keep completely dry at other times. Apply a dilute low nitrogen fertilizer fortnightly during late spring and summer

Propagation Propagate by seed or stem cuttings

Suggested planting locations and garden types Low Maintenance Patio & Container Plants

How to care

Pruning No pruning required

Pests Can be attacked by mealybugs

Diseases Generally disease free

Advertise here

Did you find the information you were looking for?

RHS members can get exclusive individual advice from the RHS Gardening Advice team.

Join the RHS now