Clustered Mountain-mint
Pycnanthemum pilosum
Last reviewed: August 2026
Pycnanthemum pilosum, or clustered mountain-mint, is a full-sun forb that blooms from June through September and draws bees, butterflies, wasps, and moths to its clustered white flowers.
Toxicity unknown
Clustered Mountain-mint (Pycnanthemum pilosum) 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
full sun
Water
medium
Size
12"–36" H × 12"–24" W
Bloom
Jun, Jul, Aug, Sep
Native to
AL, AR, CT, GA and 11 more states
Pollinators
bees, butterflies, wasps, moths
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Clustered mountain-mint is a native perennial herb that produces dense clusters of small white flowers from summer into early fall. The aromatic foliage releases a pleasant minty fragrance when brushed against, and the plant forms neat clumps that work well in sunny garden beds.
Growing Clustered Mountain-mint
Grow Clustered Mountain-mint in full sun and medium water. Mature plants reach 12 to 36 inches tall and spread 12 to 24 inches wide. Expect low maintenance to keep it looking intentional in a front yard.
How to care for Clustered Mountain-mint, by region
How to care for Clustered Mountain-mint where it is actually grown: year-round basics plus what to do each season, region by region, with the sources for each.
Care guidance last updated: September 2026
Southeastern Plains (includes Tallahassee, FL)
Year-round
Hairy mountain mint's native range covers the central and eastern United States but stops short of Florida, so growing it in Tallahassee is outside its natural range. It can still be grown here with attention to summer heat and moisture, though it is a less proven fit than it is further north.
- Choose a spot with morning sun and afternoon shade. Tallahassee summers run hotter and more humid than the mid-Atlantic and Midwest climates this plant is adapted to.
- Keep soil evenly moist through the growing season. This species declines in prolonged dry spells, and Tallahassee's sandy soils drain fast, so work in compost and mulch to help the soil hold water.
- Give it well-drained ground. Standing water during Tallahassee's summer thunderstorm season can cause root problems.
- Bees and butterflies are frequent visitors to the flower clusters in summer.
Fall
Bloom typically continues into fall in Tallahassee's long warm autumn before cooler weather finally arrives.
- Continue watering through dry fall stretches until nights turn consistently cool.
- Leave spent flower stalks standing for foraging bees and other pollinators into early fall.
- Cut back dead growth once it browns, generally later in the year here than in the plant's home range further north.
Winter
Tallahassee winters are mild, and this species is rated hardy through zone 8b, so an established planting should come through without special protection.
- No winter watering is generally needed beyond normal rainfall.
- Cut back dead top growth after a hard frost blackens it, or leave it standing over winter for wildlife and cut back in late winter instead.
- Underground rhizomes should survive Tallahassee's typically mild winter lows without mulching.
Spring
Spring is the best time to plant or divide hairy mountain mint in Tallahassee, before summer heat and humidity peak.
- Plant or transplant now while temperatures are mild, giving roots time to establish before summer heat arrives.
- Water regularly to keep soil consistently moist while the plant is settling in.
- Work compost into sandy planting beds ahead of time to improve moisture retention.
- New growth emerges from underground rhizomes. Thin crowded clumps now if last year's planting spread further than wanted.
Summer
Flowers open in summer and continue into fall, but Tallahassee's heat and humidity are more intense than this plant is used to, so afternoon shade and steady moisture matter most now.
- Provide afternoon shade where you can. Extension guidance calls for protection from intense summer heat, and Tallahassee summers run hotter and more humid than this plant's home range.
- Water during dry stretches between thunderstorms. Do not let sandy soil dry out completely for long periods.
- Watch foliage for stress or dieback in the hottest weeks. Some decline in extreme heat is possible since this planting is outside the plant's native range.
- Good air circulation between plants helps reduce fungal leaf problems in high humidity, a common issue for mint-family plants generally.
In an HOA neighborhood
Clustered Mountain-mint is an HOA-friendly choice. Maintenance level: low. Tidiness: 3 out of 5.
Works well in: mid zone, foundation.
- May spread by underground stems if not managed
- Can look sparse in winter when dormant
Wildlife value
This plant is exceptionally valuable for pollinators, attracting numerous species of bees, butterflies, beneficial wasps, and moths throughout its long blooming period. The dense flower clusters provide abundant nectar and pollen sources during peak summer months.
Common questions
- When does clustered mountain-mint bloom?
- Clustered mountain-mint typically flowers from June into September, with dense terminal clusters of small white blooms opening over several weeks in mid to late summer.
- What pollinators visit clustered mountain-mint?
- The flowers attract a wide range of bees, butterflies, wasps, and moths, making it a strong nectar source for pollinator gardens during summer.
- How much water does this plant need?
- It grows best with medium moisture but tolerates drier soil once established, so occasional dry spells are not usually a problem in a sunny garden bed.
- What growing conditions suit clustered mountain-mint best?
- It prefers full sun to part sun and average to medium moisture, growing well in open meadows, prairie plantings, and mixed perennial borders.
- Is Clustered Mountain-mint HOA-friendly?
- Clustered Mountain-mint is generally an HOA-friendly choice in the right placement, with low maintenance.
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 Clustered Mountain-mint? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.