Blue Boa Hyssop
Agastache fennelagastache 'Blue Boa'
Essentials
At a Glance
Plant Type
Perennial
Height
24 inches
Width
18 inches
Light
Full Sun, Partial Sun
Zones
5, 6, 7, 8, 9
Water
Low to moderate
Humidity
Average
Lifespan
Perennial
Native To
North America
Toxicity
Non-toxic
The Story
Plant Bio
An upright, clump-forming perennial with aromatic, lance-shaped, green leaves and long-lasting spikes of flowers that attract pollinators. Noted for its exceptionally large, dense plumes of deep violet-blue flowers that bloom for a long period from summer to fall.
Uses & Benefits:
Marketplace
Where to Buy
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Planting
How to Grow
- Tuck seeds into well-draining soil in early spring.
- Mist cuttings regularly to maintain humidity for 6 weeks.
- Provide full sun for optimal growth.
- Water deeply once a week during dry periods.
- Fertilize monthly with a balanced fertilizer in spring and summer.
- Prune after flowering to encourage bushy growth.
Pro Tip
Use well-draining sandy soil and avoid overwatering for best results.
Keep It Thriving
Care Guide
Do
- Water regularly during dry spells 🌱
- Prune after flowering to promote new growth 🌱
- Apply balanced fertilizer monthly in growing season 🌱
- Ensure full sun exposure for vibrant blooms 🌱
Don't
- Overwater to prevent root rot ❌
- Allow soil to become waterlogged ❌
- Skip pruning after flowering ❌
- Plant in dense, clay soils without amendment ❌
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Deadhead | ||||||||||||
| Divide | ||||||||||||
| Fertilize | ||||||||||||
| Plant | ||||||||||||
| Spring Cleanup |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Companion Plants
Multiply
Propagation Methods
Good to Know
Common Questions
Blue Boa Hyssop questions
What zones can Blue Boa Hyssop grow in?
Blue Boa Hyssop is hardy in USDA Zones 5–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Blue Boa Hyssop deer resistant?
Yes — Blue Boa Hyssop is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does Blue Boa Hyssop bloom?
Blue Boa Hyssop typically blooms in summer to fall through late summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Blue Boa Hyssop need full sun?
Blue Boa Hyssop does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
Is Blue Boa Hyssop drought tolerant?
Yes — once established (usually after the first full season), Blue Boa Hyssop handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.
More Agastache to compare
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Agastache x hybrida 'Mix'
Kudos Ambrosia Anise Hyssop
Agastache foeniculum 'Kudos Ambrosia'
Anise Hyssop
Agastache foeniculum 'Poquito Butter Yellow'
Anise Hyssop
Agastache foeniculum
Anise Hyssop
Agastache foeniculum 'Sunrise Blue'
Keep exploring
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Grow Blue Boa Hyssop with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.
