• A close-up of Agastache foeniculum (Giant Hyssop) showcasing its dense, cylindrical purple flower spikes. The flowers are surrounded by bright green, serrated leaves, creating a striking contrast.
  • A field of Agastache foeniculum (Giant Hyssop) plants in full bloom. Tall spikes of purple flowers rise above the green foliage, attracting pollinators in a sunlit meadow.
  • A detailed view of Agastache foeniculum (Giant Hyssop) leaves. The green, serrated foliage has a slightly fuzzy texture and emits a licorice-mint fragrance when crushed.
  • A mature Agastache foeniculum (Giant Hyssop) plant growing in a garden. Tall flower spikes covered in tiny purple blossoms rise above the leafy stems, with other native plants in the background.
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Wild About Flowers

Agastache foeniculum - Giant Hyssop

Agastache foeniculum - Giant Hyssop

$5.00 CAD
$5.00 CAD
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Giant Hyssop is a hardy, upright perennial known for its dense spikes of fragrant purple flowers that bloom from mid-summer into early fall. Its anise-scented foliage adds another sensory dimension, making it a standout in pollinator gardens, herbal borders, and prairie plantings. The tall, showy blooms are rich in nectar and act as a magnet for native bees, butterflies, and hummingbirds, offering extended seasonal support for pollinators.

Naturally found in dry prairies, open woodlands, and well-drained slopes, Giant Hyssop is highly drought-tolerant once established. It pairs beautifully with other sun-loving wildflowers and ornamental grasses, adding vertical interest and fragrance to naturalized landscapes. Its strong scent and aromatic foliage deter deer, giving it reliable resistance to grazing.

How Easy Is This Plant to Grow?

Germination Difficulty: Beginner
Growing Difficulty: Beginner
Speed of Growth: Moderate/Fast
Age to First Bloom: 1-2

Plant Sizes & Blooming Window

Important Information - The "Plant Sizes" are provided as a general guideline for plant selection. The "Blooming Window" indicates the general period when the species is in bloom, not how long an individual plant will flower.

Plant growth and bloom times will vary depending on geographical location & individual site conditions. Please scroll down to see the specific information for this plant.

Edible & Medicinal Info Disclaimer

The Edible & Medicinal information on this site is for informational purposes only and should not be acted on without thorough research and professional guidance. We are not responsible for any adverse effects resulting from the use of or misidentification of plants.

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Plant Specifics

Seeds Per Pack

Seeds Per Package: 35

Light Conditions

  • Sun
  • Part Shade

Soil Conditions

  • Loam

Height

  • 24" - 36"
  • 36" - 48"

Width

  • 12" - 24"
  • 24" - 36"

Bloom Colour

  • Blue

Month of Bloom

  • July
  • August
  • Septemeber

Vigorousness

  • Moderate
  • Fast

Deer Resistance

  • High

Features

  • Birds
  • Butterflies
  • Bees
  • Fragrant
  • Long Bloom Time
  • Urban Spaces
  • Rural Spaces
  • Medicinal Properties
  • Edible Parts
  • Good in Containers

Chinook Exposure

  • Fully Exposed

Distribution Info

Native to Canada, Giant Hyssop is found throughout Alberta, BC, and SK and across the country, thriving in open grasslands, meadows, and woodland edges. Its range extends across much of North America.

Traditional Edible & Medicinal Info

Giant Hyssop has been traditionally used in herbal medicine for teas, digestive support, and respiratory health. The leaves and flowers are edible, with a mild licorice flavor that can be used fresh or dried.