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Giant Hyssop in the GardenTags plant encyclopedia

Agastache 'Black Adder'

 

Giant Hyssop

Agastache is an upright, aromatic flowering herbaceous perennial plant, 0.5–3 m tall, with rigid stems and lance shaped, toothed leaves. The flowers are usually white, pink, mauve, or purple and appear in summer. They are easily grown in moist, well-drained soil and prefer a sunny position. The grow best in alkaline soil but will tolerate poor acid soils. 'Black Adder' sports tall, long lasting violet flower spikes, scented foliage and great for bees. Short lived perennial, treated as an annual in colder areas due to its borderline hardiness.

Contributed by @gardengimp

 
plant Features
  • Giant Hyssop likes full sun

    Full sun

  • Giant Hyssop likes very little water

    Very little water

  • Giant Hyssop is frost hardy: 23f (-5°c)

    Frost Hardy: 23F (-5°C)

  • Giant Hyssop likes moist and free draining

    Moist and free draining

 
plant information

Common name

Giant Hyssop

Latin name

Agastache 'Black Adder'

type

Perennial

family

Lamiaceae

ph

6.5 - 8.0 Acid - Neutral

  • Light

    Giant Hyssop likes full sun

    Full sun

  • Frost

    Giant Hyssop is frost hardy: 23f (-5°c)

    Frost Hardy: 23F (-5°C)

  • Soil

    Giant Hyssop likes moist and free draining

    Moist and free draining

  • Water

    Giant Hyssop likes very little water

    Very little water

Plant & bloom calendar

  •  
    Best time to plant

full grown dimensions

The size of a fully grown Giant Hyssop is 0.50meters x 2.00meters 0.50 M 2.00 M

Agastache 'Black Adder'

Agastache is an upright, aromatic flowering herbaceous perennial plant, 0.5–3 m tall, with rigid stems and lance shaped, toothed leaves. The flowers are usually white, pink, mauve, or purple and appear in summer. They are easily grown in moist, well-drained soil and prefer a sunny position. The grow best in alkaline soil but will tolerate poor acid soils. 'Black Adder' sports tall, long lasting violet flower spikes, scented foliage and great for bees. Short lived perennial, treated as an annual in colder areas due to its borderline hardiness.


Planting

From Early Spring TO Early Spring

Plant young plants 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. Water newly-planted agastache regularly, until it is established. Once established it can tolerate a certain amount of drought, so would only need watering in prolonged dry spells of weather

 

Propagation by division.

From Early Spring TO Early Spring

Propagate by division in spring or propagate by semi-ripe cuttings in late summer for overwintering under cover. To divide, place two hand forks back-to-back near the middle of the plant. Gently push the handles back and forth so that the prongs gradually tease the plant apart. Repeat the process with each portion to divide the plant into more sections, making sure each section has a healthy bud.

 
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