How to Grow Agastache
Wikimedia Commons
Agastache
Agastache spp.
herbAgastache is a fragrant perennial herb featuring tall spikes of colorful flowers in shades of purple, pink, orange, and blue that attract pollinators. Also known as hyssop or giant hyssop, it combines ornamental beauty with culinary and medicinal uses. The foliage is aromatic with anise or mint-like scents depending on the variety.
Looking for a specific variety?
When should you plant Agastache in your zone?
Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.
Example Agastache timeline · Pittsburgh, PA (Zone 6b)
-
Plant Agastache
Around Apr 17Near Pittsburgh's average last spring frost.
-
Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
-
Harvest Agastache
Around Jun 16≈ 60 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Agastache dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 5-9; some cold-hardy varieties tolerate zones 3-4
Sign up free to see if Agastache grows in your zone — and get a personalized planting timeline.
Get my Agastache timeline →Growth Stages
Germination & Seedling
2-3 weeksTiny seedlings with first true leaves appear within 7-14 days. Plants are delicate and require consistent moisture without waterlogging.
Keep soil consistently moist but not soggy. Provide bright light. Thin seedlings to prevent crowding. Avoid damping off by ensuring good air circulation.
Vegetative Growth
4-6 weeksPlant develops sturdy stems and increasingly aromatic foliage. Height increases rapidly; multiple stems form from the base. Leaves are lance-shaped and textured.
Water moderately as soil dries. Begin light feeding with balanced fertilizer every 2-3 weeks. Pinch growing tips early to encourage bushier growth. Ensure full sun exposure.
Budding & Flowering
4-8 weeksDense flower spikes form at stem tips, developing from bottom upward. Colors intensify; flowers begin opening in sequence along the spike.
Reduce nitrogen fertilizer; switch to lower-nitrogen formula to encourage flowering. Deadhead spent flowers to extend blooming season. Provide consistent watering but allow slight drying between waterings.
Peak Bloom & Seed Set
6-12 weeksFull flower spikes attract bees, butterflies, and hummingbirds. If flowers go unpollinated, seeds begin developing within the flower spike.
Continue deadheading for continuous blooms through mid-fall, or allow some flowers to mature for seed collection. Minimal fertilizing needed. Maintain steady water supply.
Senescence & Dormancy
Variable (fall-winter)Foliage begins to fade; stems may brown. In cold climates, plant dies back to ground. In mild zones, evergreen varieties retain foliage.
Cut back dead stems in fall or early spring. Do not apply heavy mulch in winter in humid areas; it promotes rot. In zones 3-4, provide light mulch after ground freezes. Allow self-seeding if desired.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
-
Increase humidity by misting; use insecticidal soap or neem oil spray if infestation occurs. Remove heavily infested leaves.
-
Yellow sticky traps; strong water spray to dislodge; neem oil or insecticidal soap for heavy infestations.
-
Ensure good air circulation; avoid overhead watering. Apply sulfur dust or fungicide if needed. Remove affected leaves.
-
Remove infected leaves immediately. Improve air circulation. Apply copper fungicide if severe; avoid overhead watering.
Uses
Herbal teas and beverages
CulinaryFresh or dried agastache leaves brew into aromatic tea with a pleasant anise or mint flavor, served hot or iced. The flowers and leaves are also used to infuse cocktails, lemonades, and other beverages. [source]
Seasoning and garnish
CulinaryBoth leaves and colorful flowers can flavor dishes, garnish salads, and add an ornamental touch to desserts and cocktails. The anise notes complement Asian and Mexican cuisines. [source]
Traditional cold and cough remedy
MedicinalAgastache tea is traditionally used in Chinese and Native American medicine to support respiratory health and soothe mild coughs and sore throats. Contains volatile essential oils with antimicrobial properties. [source]
Pollinator attraction
WildlifeAgastache flowers are highly attractive to bees, butterflies, and hummingbirds, making it an excellent plant for supporting pollinator populations and enhancing garden biodiversity. [source]
Natural fragrance and dried arrangements
HouseholdDried agastache spikes retain their aromatic qualities and attractive colors, making them ideal for dried flower arrangements, potpourri, and natural fragrancing of spaces. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Harvest leaves and flower spikes in the morning after dew dries for maximum essential oil content. Pinch top 1/4 to 1/3 of stems regularly to encourage bushiness and continuous flowering. For drying, cut stems just as flowers begin opening. Hang-dry in bundles in a warm, airy location. Store dried agastache in airtight containers away from light. Fresh leaves can be harvested throughout the growing season.
Fun Facts
- 🌱 The name 'Agastache' comes from Greek words meaning 'much' (aga) and 'ear of grain' (stachis), referring to the dense flower spikes.
- 🌱 Agastache is a keystone plant in pollinator gardens—a single flowering plant can attract dozens of butterfly and bee species throughout the blooming season.
- 🌱 Many Agastache species are native to Mexico, the southwestern United States, and Asia; different varieties carry distinct flavor profiles ranging from anise and licorice to mint and bubble gum.
Gardening Terms
New to gardening? Learn about terms used in this guide:
Join 30,000 gardeners planning their gardens with LizPlants.
Get your personalized Agastache planting timeline
Tell us your zip code and we'll calculate exactly when to start Agastache seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.
Get my Agastache timeline →