Giant Blue Hyssop
Agastache foeniculum
Fragrant purple-blue spikes bloom midsummer through September and draw more bees than almost anything else. Rub a leaf for the anise-mint scent.
Typically 1 pint–1 gal · $9–$30 · final price at pickup
- Thu, Aug 138 AM – 4 PM
- Fri, Aug 148 AM – 4 PM
- Sat, Aug 158 AM – 2 PM
Native pollinators treat this plant like a landing strip. the sustained midsummer bloom and fragrance make it one of the highest-value perennials we carry.
Giant Blue Hyssop is native Agastache at its most impressive: a four to five foot column of fragrant, purple-blue flower spikes that bloom from midsummer through September and draw more bees per square foot than almost anything else in the summer garden. Rub a leaf and you get a clean, anise-mint scent that hangs in the air. The flowers are a true purple-blue, stacked in dense whorls along upright stems, and the show continues for months as each spike opens progressively from base to tip. This is a plant that earns its space through sheer ecological performance. Native bees, especially bumblebees and smaller specialist bees, work the flowers from morning to dusk. Hummingbirds and clearwing moths join the rotation. In late summer when other nectar sources dry up, Giant Blue Hyssop becomes the anchor of the pollinator garden. It self-sows modestly in open spots but isn't weedy, and the seedlings are easy to manage or transplant.
A nursery-grown plant, ready for the ground.
Healthy, container-grown giant blue hyssop propagated on-site at Hill House from regional genetics. Includes a one-page care card. We make every effort to supply plants as listed; occasionally we substitute a similar species of equal value.
- Sun
- Full sun
- Water
- Average
- Mature size
- 3–5 ft · 18–30 in wide
- Bloom time
- Midsummer through fall
- USDA zones
- 4–8
- Family
- Lamiaceae
- Native range
- Eastern and central North America, from Ontario south through the mid-Atlantic and Midwest
Care notes for giant blue hyssop.
Grow in full to part sun with good drainage. Established plants are drought tolerant and thrive in lean soil. excess fertility produces floppy growth with fewer flowers. Deadhead spent spikes to encourage reblooming, or leave them standing for seed-eating birds through winter. Cut to the ground in early spring. Divide every three to four years to prevent crowding at the crown.
Pairs well with these.
Same light, same soil, same wildlife. Janet's picks to plant alongside giant blue hyssop.
Or skip the guesswork.
Curated packages bundle complementary species for an instant habitat. One reservation, one pickup day, a printed layout map.
Short on Space Package
For gardeners who have an abundance of passion but are short on space, this package features tidy, upright, clump-forming natives that behave and function well in small spaces.
Shade Bed Package
Ferns, sedges, and woodland natives that thrive under existing trees.
Birder’s Paradise Package
For the avid bird watchers and budding ornithologists in our community, the Birder’s Paradise Package consists of species that Hill House Nursery staff and longtime native plant advocates such as Doug Tallamy consider ‘premier bird garden plants’.