SafePlants

Giant Hyssop (Agastache)

Giant Hyssop, belonging to the Agastache genus, is a group of aromatic flowering herbaceous perennial plants cherished for their attractive spikes of flowers and fragrant foliage.

Considerations for Pets

• The text mentions that Agastache has aromatic leaves. Aromatic plants may cause mild irritation if ingested by some pets.

Considerations for Children

• Giant Hyssop is known to have edible leaves and flowers.

Taxonomy and Nomenclature

• Genus: Agastache
• Family: Lamiaceae (also known as Labiatae or Mint family)
• Synonyms:
  • Cedronella mexicana (synonym for Agastache mexicanum)
  • Hyssopus nepetoides (synonym for Agastache nepetoides)
  • Lophanthus nepetoides (synonym for Agastache nepetoides)
  • Agastache urticifolia var. urticifola (synonym for Agastache urticifolia)

Common Names

• Giant Hyssop
• Anise Hyssop
• Blue Giant Hyssop
• Fragrant Giant Hyssop
• Lavender Hyssop
• Mexican Giant Hyssop
• Korean Hyssop
• Purple Giant Hyssop
• Yellow Giant Hyssop
• Elk Mint
• Licorice Mint
• Wild Anise

Cultivars

• 'Blue Fortune'
• 'Tutti-frutti'
• 'Black Adder'
• 'Sangria' (Agastache mexicana 'Sangria')
• 'Snow Spike' (white-flowered cultivar)

Distribution and Habitat

• Native to eastern Asia (one species) and North America (most species).
• Purple Giant Hyssop is found in rich, moist woods and along river banks.
• Blue Giant Hyssop grows in prairies and open woodlands on dry, sandy, gravelly, sometimes silty soil.
• Grows wild across the central prairie regions of the United States and Canada.

Morphological Characteristics and Growth Habits

• Herbaceous perennials.
• Upright growth habit.
• Typically grows to a height of 4-7 feet (1.2-2.1 metres) and spreads 1-3 feet (0.3-0.9 metres).
• Features opposing leaves and tall, strong central stems.
• Slender soft-lavender spikes of flowers held in darker bracts.
• Square stems (as found in Blue Giant Hyssop).
• Some species have aromatic foliage, with scents like anise or licorice.
• Tubular flowers arranged in dense spikes.

Ecological Role

• Attracts bees and butterflies.
• Essential oil from Giant Hyssop (Agastache foeniculum) has shown to be an effective insecticide against several species.

Interactions with Other Organisms

• Flowers are attractive to bees and butterflies.

Quirky Facts

• The genus name Agastache describes the flower clusters.
• Edible leaves and flowers taste like a combination of mint and aniseed.
• Native Americans used the rough leaves of Purple Giant Hyssop.

Further Information

• USDA NRCS Cape May Plant Materials Center
• Dave's Garden (online community)
• Toadshade Wildflower Farm