Yellow Giant-hyssop
Agastache nepetoides
Last reviewed: September 2026
Agastache nepetoides is an upright forb that blooms from July through September with tall spikes of yellow-green flowers. It grows well in part sun to full sun and medium to slightly dry soil along woodland edges and thickets.
Toxicity unknown
Yellow Giant-hyssop (Agastache nepetoides) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.
Light
part sun
Water
medium
Size
36"–72" H × 18"–24" W
Bloom
Jul, Aug, Sep
Native to
AL, AR, CT, GA and 17 more states
Pollinators
bees, butterflies, hummingbirds
Before you buy
Your city may pay you to plant this
Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 452 programs across 44 states, each with a link to the provider and the date we last checked it.
Find rebates in your areaBrowse plants for this ecoregion
Yellow giant-hyssop is a tall native perennial with spikes of small, pale yellow flowers that bloom from summer into fall. This upright plant forms clumps and can reach up to 6 feet tall, making it an excellent choice for back borders or naturalized areas.
Growing Yellow Giant-hyssop
Grow Yellow Giant-hyssop in part sun and medium water. Mature plants reach 36 to 72 inches tall and spread 18 to 24 inches wide. Expect low maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
Yellow Giant-hyssop takes more care to keep looking intentional in a front yard. Maintenance level: low. Consider it for backyard or mid-zone beds rather than the street edge.
Works well in: backyard only.
- Very tall height may appear unmanaged
- Can look weedy when dormant
- Flowers are not showy enough for formal landscapes
Wildlife value
This plant is a pollinator magnet, attracting bees, butterflies, and hummingbirds with its long blooming period. The seeds also provide food for finches and other small birds in late fall.
Common questions
- When does Yellow Giant-hyssop bloom?
- Yellow Giant-hyssop typically blooms from July through September, producing dense spikes of small yellow-green flowers.
- What growing conditions suit Yellow Giant-hyssop best?
- This plant does well in part sun to full sun with medium moisture soil, though it tolerates somewhat drier conditions once established. It is often found at woodland edges, in thickets, and along stream banks.
- What pollinators visit Yellow Giant-hyssop?
- Bees, butterflies, and hummingbirds are regularly seen visiting the flower spikes for nectar during the summer bloom period.
- Is Yellow Giant-hyssop a shrub or a perennial?
- It is an herbaceous forb, dying back to the ground each year rather than growing as a woody shrub.
- Is Yellow Giant-hyssop HOA-friendly?
- Yellow Giant-hyssop takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.
These answers were drafted with an AI model from this plant's data. Verify care details with a local expert.
Native range data from the World Checklist of Vascular Plants (Kew). Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
If something looks wrong
Common plant problems, and what to check first
These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.
- It is dying right after planting
- Leaves turning yellow
- Wilting even though I watered it
- Brown crispy leaf tips
- Bugs on the plant
Ready to grow Yellow Giant-hyssop? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
Planning a bed around it? Start a free plan with this plant
Not sure where to start? Take the 2-minute yard quiz