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Blue Giant Hyssop (Agastache foeniculum) is an exceptionally cold-hardy Hyssop that blooms for many months with smoky-blue flowers held above attractive, aromatic foliage. It is native to the Mid-west.
To determine if a plant is sufficiently cold hardy, the USDA created numbered zones indicating winter low
temperatures; the lower the zone number the colder the winter.
If the coldest winter temperature expected in your area is -15°F (zone 5) then any plants rated zones 3-5 will
survive the winter temperatures in your area.
If you live in very warm winter areas (zones 9-11) plants with zones 3-4 ratings are not recommended. The lack
of freezing winter temperatures do not provide a time for winter dormancy (rest).
Agastache foeniculum (Blue Giant Hyssop), a native to the northern tier states and Canada, this exceptionally cold hardy Hyssop blooms for many months with smoky-blue flowers held above attractive, aromatic foliage. An outstanding perennial for attracting bees and butterflies with its nectar-rich flowers, Agastache foenicuum is highly recommended for gardeners in the moister eastern half of the country, where more xeric Hyssops (Hummingbird mints) like Agastache rupestris and Agastache cana will struggle.
More Information
SKU
HC015393
Item Package Size
Plant - 5" Deep Pot
Common Name
Blue Giant Hyssop
Botanical Name
Agastache foeniculum
Zones
4, 5, 6, 7, 8
Light Requirements
Full Sun
Flower Color
Blue
Mature Height
30-36" tall
Mature Spread
15-18" wide
Bloom Time
Mid to late summer
Ships As
Potted Plant
Soil Type
Average Soil
Soil Moisture
Waterwise, Average
Advantages
Attract Butterflies, Deer Resistant, Native, Extended Bloom Time (more than 4 weeks), Fragrant Flower / Foliage, Rabbit Resistant
Ideal Region
Anywhere In The US, Northeast, Midwest, West, Southwest, Pacific Northwest
Planting Time
Spring / Summer, Fall
Native To
North America
Ships To Canada
No
Planting Guides
Tips for growing Agastache
Agastache are sun loving plants with aromatic foliage and flowers. They bloom from mid-summer into early fall and are resistant to rabbits and deer.
Agastache need lean, well-drained soils, prefer gravel mulches, and appreciate deep but infrequent watering after their second growing season
Provide a fast draining soil that's naturally low in fertility, Don't plant into clay soils.
Plant in full hot sun.
Just a few handfuls of compost in the planting hole is enough. Don't plant into a rich, highly amended soil..
Fertilize the Agastache just once in fall with Yum Yum Mix.
New transplants need regular irrigation their first growing season to establish themselves. Watering can be reduced greatly during the second growing season when the plants have matured.
To improve winter-hardiness, and encourage re-seeding, leave the stems intact over the winter. In mid-spring, remove old stems just above the new foliage, about 4 or 5 inches above ground level.
If your conditions don't lend themselves to growing Agastache in your garden, they do well planted in containers.
View more Planting Guides, or download our complete Planting Guide for tips on caring for your plants when you receive your order, as well as planting instructions for Perennials, Spring-Planted Bulbs, Fall-Planted Bulbs, Cacti & Succulents, Xeric Plants and more.
Shipping
No longer available this season.
As soon as your order is placed you will receive a confirmation email. You will receive a second email the day your order ships telling you how it has been sent. Some perennials are shipped as potted plants, some as perennial roots packed in peat. The ‘Plant Information’ section describes how that item will ship. All perennials and spring-planted bulbs are packaged to withstand shipping and are fully-guaranteed. Please open upon receipt and follow the instructions included.
Perennials and spring-planted bulbs are shipped at the proper planting time for your hardiness zone. Perennial and spring-planted bulb orders will arrive separately from seeds. If your order requires more than one shipment and all items are shipping to the same address, there is no additional shipping charge. See our shipping information page for approximate ship dates and more detailed information. If you have any questions, please call Customer Service toll-free at (800) 925-9387 or contact us by email.
Shipping Rates
Our shipping rates are calculated based on our actual average shipping costs. We do not seek to profit from shipping fees, so rest assured that our shipping rates reflect an average of what it costs to get our guaranteed products safely to your door.
US Shipping Charges
Merchandise Total
Shipping Charges
Up to $19.99
$8.99
$20 to $34.99
$10.99
$35 to $49.99
$12.99
$50 to $74.99
$14.99
$75 to $99.99
$16.99
$100 and Over
$18.99
Canadian Shipping Charges
Merchandise
Shipping Charges
Up to $24.99
$14.95
$25 to $49.99
$19.95
$50 to $74.99
$24.95
$75 to $99.99
$29.95
$100 and Over
$39.95
We charge one low flat rate for shipping our products even if your order requires multiple shipments. If you have any questions, please call us at (800) 925-9387.
 is an exceptionally cold-hardy Hyssop that blooms for many months with smoky-blue flowers held above attractive, aromatic foliage. It is native to the Mid-west.)
