Content Detail

Thread-leaved giant-hyssop is a striking, hardy perennial with slender, branched, gray-green foliage and rosy-orange tubular flowers.

  • Family (English) Mint
  • Family (botanic) Labaceae
  • Tree or plant type Perennial
  • Native locale North America
  • Size range Large plant (more than 24 inches)
  • Light exposure Full sun (6 hrs direct light daily)
  • Hardiness zones Zone 5 (Chicago), Zone 6, Zone 7, Zone 8
  • Soil preference Moist, well-drained soil
  • Tolerances Alkaline soil, Occasional drought
  • Season of interest midsummer, late summer, early fall
  • Flower color and fragrance Fragrant, Blue
  • Shape or form Multi-stemmed, Upright
  • Growth rate Moderate

Size:

A clump-forming perennial;  upright, 2 to 3 feet high and 2 feet wide.

Native geographic location and habitat: 

Found in the mountains of southwestern NM to central AZ and south into northern Mexico

Attracts birds or pollinators: 

Butterflies, bees, hummingbirds and other pollinators

Leaf description: 

Thread-like, gray-green, 2-inch long linear leaves; anise or licorice-scented; erect square stems

Flower description: 

Tubular-shaped, burnt-orange flowers on a long inflorescence.

Fruit description:

Seeds are small nutlets

Plant care:

Thread-leaved giant-hyssop is an excellent choice for dry sunny areas in the garden.  Full sun in well-drained soil is a must. Intolerant of wet sites or high humidity.  Does poorly in wet areas.  Cut back plants in spring to promote new growth.

Cultivars and related hybrids:  Hybrids are usually showier and hardier and come in a wide variety of colors. Most are 2 to 4 feet high with fragrant, licorice-scented gray-green foliage.  

Desert Sunrise hyssop (Agastache ‘Desert Sunrise’):

3 to 4 feet high and 2 feet wide; orange-pink and lavender flowers.

Firebird hyssop (Agastache ‘Firebird’): 

2 to 3 feet high and 2 feet wide; long terminal spikes of orange-copper flowers.

Tutti-frutti giant hyssop (Agastache pallida x A. mexicana ‘Tutti-Frutti’):

2 1/2 feet high and 1 to 1 1/2 feet wide; 6 to 10 inch terminal spikes of tubular-shaped raspberry flowers.

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