Pycnanthemum muticum (blunt mountain mint)
Overview
Scientific name: Pycnanthemum muticum
Common names: Blunt mountain mint, short-toothed mountain mint, clustered mountain mint
Family: Lamiaceae (Mint family)
Native range: Eastern and central North America – from New England and the Midwest south to Florida and Texas.
Habitats: Moist meadows, woodland edges, open prairies, and savannas; tolerates disturbed areas with adequate moisture.
Growth habit:
Perennial; clump-forming but spreads moderately by rhizomes.
Height: 2–3 feet tall.
Leaves: Fragrant, opposite, oval; emit a strong minty aroma when crushed.
Flowers: Dense clusters of tiny pinkish-white tubular flowers; surrounded by silvery bracts that give a frosted appearance.
Bloom period: Mid- to late summer (July–September).
Ecological Role
1. Keystone Nectar Plant
Produces extremely nectar-rich flowers that attract a vast array of pollinators.
Considered one of the most pollinator-dense native plants in North American prairies and meadows.
2. Supports Pollinator Biodiversity
Attracts native bees (sweat bees, bumble bees, leafcutter bees, resin bees), wasps (sand wasps, great golden digger wasps, potter wasps), butterflies, skippers, moths, and flies.
Supports beneficial predatory wasps that control pests (e.g., caterpillars, leafhoppers, grasshoppers).
3. Aromatic Defense
Strong aromatic oils deter mammalian herbivory (e.g., deer, rabbits).
These oils also have antimicrobial properties, historically used by Indigenous peoples for medicinal purposes.
4. Summer-Fall Forage Bridge
Fills a nectar gap in mid to late summer, when early summer blooms (e.g., penstemons, milkweeds) are finished and before goldenrods/asters dominate in fall.
Essential for sustaining pollinators during critical summer brood rearing and pre-migration fattening (e.g., monarchs).
5. Soil and Habitat Benefits
Deep roots help stabilize soil in meadow restorations.
Clump-forming habit suppresses weeds, supporting prairie diversity without becoming aggressive.
Wildlife Supported
Pollinators
Native bees: Sweat bees (Lasioglossum, Halictus), bumble bees (Bombus spp.), leafcutter bees (Megachile spp.), carpenter bees.
Wasps: Great golden digger wasp (Sphex ichneumoneus), cicada killer (Sphecius speciosus), sand wasps (Bembix spp.), thread-waisted wasps (Ammophila spp.), potter wasps.
Butterflies and skippers: Common buckeye (Junonia coenia), clouded sulphur (Colias philodice), silver-spotted skipper (Epargyreus clarus).
Flies and beetles: Syrphid flies (hoverflies), soldier beetles.
Birds
Indirect support: attracts insects that are eaten by songbirds (e.g., flycatchers, warblers).
Mammals
Low browse pressure due to aromatic foliage; not a primary food source.
Growth and Planting Notes
Sunlight: Full sun to part shade (best flowering in full sun).
Soil: Moist to medium; tolerates clay or sandy loam.
Spread: Rhizomatous but manageable; forms dense, pollinator-friendly clumps.
Maintenance:
Cut back in late winter or early spring.
Allow stems to remain standing over winter for beneficial insect overwintering.
Companion Plants
Pair with other mid-to-late summer natives for layered bloom and structure:
Conservation and Restoration Value
Widely used in prairie restorations, pollinator gardens, and meadows due to its exceptional insect diversity support.
Functions as a magnet species: attracts pollinators to the site, increasing pollination of nearby plants.
High value for beneficial wasp populations, which in turn control herbivorous insects naturally.
Key Ecological Takeaways
High nectar production = supports hundreds of pollinator species.
Aromatic foliage = deer- and rabbit-resistant, ideal for diverse plantings.
Seasonal gap filler = sustains pollinators mid-late summer.
Supports predatory wasps = indirectly enhances ecosystem pest control.
Easy to grow and resilient = excellent for gardens and large-scale restorations.
