Species Native to Missouri
Common Name: American mountain mint
Type: Herbaceous perennial
Family: Lamiaceae
Native Range: Eastern and central United States
Zone: 4 to 8
Height: 1.00 to 3.00 feet
Spread: 1.00 to 3.00 feet
Bloom Time: July to September
Bloom Description: White
Sun: Full sun to part shade
Water: Dry to medium
Maintenance: Low
Suggested Use: Naturalize
Flower: Showy
Leaf: Fragrant
Attracts: Butterflies
Tolerate: Drought, Erosion, Dry Soil
Culture
Easily grown in average, dry to medium, well-drained soils in full sun to part shade. Best flowering is in full sun. This plant is a vigorous grower that may spread by rhizomes in optimum conditions. If naturalizing is unwanted, prune roots in spring with a spade to keep clumps from spreading.
Noteworthy Characteristics
Pycnanthemum pilosum, commonly called hairy mountain mint, is a clump-forming perennial that typically grows 1-3’ tall. It is native from Ontario to Michigan to Iowa south to Tennessee, Arkansas and Oklahoma. In Missouri, this Pycnanthemum is indigenous to prairies, open dry and upland woodlands, thickets and along railroads throughout most of the state except the lowland southeastern counties (Steyermark). Features small, two-lipped, white (sometimes lavender-tinged) flowers with purple spotting in mid to late summer. Flowers appear in both terminal and axillary clusters (to 1.5” wide). Leaves (to 3” long) are narrow (3/4” wide) and noted for being very aromatic when bruised. In comparison to other Pycnanthemums, its leaves are broader and short-stalked. Flower clusters are attractive to bees.
Genus name comes from Greek pyknos meaning dense and anthos meaning flower for its densely packed flowers.
Specific epithet means covered with fine hairs.
Problems
No serious insect or disease problems. Plants can spread.
Uses
Best when allowed to naturalize in native plant gardens, rock gardens, dry meadows or herb gardens. May be planted in border perimeters as long as spread is monitored, but most gardeners do not consider this plant to have sufficient ornamental merit for a prominent position in the garden.