Hoary mountain mint is an herbaceous perennial in the mint family (Lamiaceae). It is native in the eastern United States to Indiana. The species epithet is Latin for “gray” and refers to the color of the foliage. It is an erect, many-branched perennial that typically grows 2 to 3 feet tall on square stems in full sun to partial shade. It is drought tolerant and grows well even in dry soils. However, it prefers moist soil with good drainage. It roots by stems and self seeds easily, naturalizing in a landscape, so be aware of its weedy tendencies. This plant will need a space 2 to 4 feet wide with the possibility of height up to 6 feet. Hoary mountain mint can be used to help stop erosion and provides nectar for pollinators. This plant is attractive to butterflies and other insects, and is highly deer resistant. Hoary mountain mint may grow tall and is best suited for naturalized or woodland areas. It also works well in butterfly, edible, native and pollinator gardens. Insects, Diseases and Other Plant Problems: No serious insect or disease problems. Plant is weedy. More information on Pycnanthemum .
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil drainage
Good Drainage | Moist | Occasionally Dry
Available space
12 inches-3 feet
NC region
Mountains; Piedmont
Mature size
Height: 3 ft. 0 in. - 6 ft. 0 in. | Width: 2 ft. 0 in. - 4 ft. 0 in.
Maintenance
Low
Canopy layer
4 - Herbaceous (3-15 ft)
Form & Appearance
Habit / form
Erect
Foliage
Deciduous
Leaf color
Gray/Silver; Green; White
Leaf type
Simple
Leaf arrangement
Opposite
Leaf shape
Lanceolate; Ovate
Leaf margin
Dentate
Leaf feel
Soft
Leaf value
Edible; Fragrant; Good Dried
Leaf size
1-3 inches long, 1-3 inches wide
Hairs present
Yes
Leaf detail
1.5 to 4 in. egg- to lance-shaped, toothed, opposite, stalked leaves with white down (hoary) below.
Flower color
Purple/Lavender; White
Flower value
Fragrant; Showy
Flower form
Cyme
Flower shape
Lipped
Flower size
< 1 inch
Flower detail
Cluster of small, lobed, two-lipped, whitish to lavender flowers with small purple spots; hoary bracts below the flower. Blooms June to August.
Bloom time
Summer
Fruit color
Black
Fruit type
Capsule
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
Displays from September to October.
Stem color
Gray/Silver; Green; White
Stem detail
Hoary stems
Wildlife & Ecology
Native status
Native
Origin
Eastern U.S.A. to Indiana
Wildlife value
This plant supports Wavy-lined Emerald (Synchlora aerata) larvae. This plant provides nectar for pollinators. Flowers are attractive to butterflies, especially smaller species like hairstreaks, and many other insects.