• 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

Agastache 'Blue Fortune'

giant hyssop 'Blue Fortune'

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
  • Other common names giant hyssop 'Blue Fortune'

  • Family Lamiaceae

  • Genus Agastache are herbaceous perennials with simple, aromatic leaves and small 2-lipped tubular flowers in whorls forming dense spikes, in summer and autumn; some are rather tender but can be grown as annual bedding

  • Details 'Blue Fortune' is an upright deciduous perennial forming a clump of leafy stems, with dense, interrupted spikes of small violet-blue flowers from summer to early autumn

Characteristics

  • Foliage Deciduous

  • Habit Bushy

  • Fragrance Leaf

  • 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)

    H6

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or West-facing

  • Exposure Exposed or Sheltered

Soil

  • Chalk

    Sand

  • Chalk

    Clay

  • Chalk

    Chalk

  • Chalk

    Loam

  • MoistureWell-drained, Moist but well-drained

  • SoilSand, Clay, Chalk, Loam

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 0.5-1 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation Can be used as a gap-filler in herb gardens or in sunny, dry places, for example at the base of walls. Grows best in well-drained alkaline soil but will tolerate poor acid soils. Tends to be short-lived

Propagation Propagate by division. This cultivar is sterile

Suggested planting locations and garden types Banks and Slopes Flower borders and beds Cottage & Informal Garden Gravel Garden Mediterranean Climate Plants

How to care

Pruning Remove spent flowering spikes through the season

Pests Generally pest free

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