Pycnanthemum setosum

Common Name: mountain mint 
Type: Herbaceous perennial
Family: Lamiaceae
Native Range: Eastern United States
Zone: 5 to 9
Height: 1.00 to 3.00 feet
Spread: 1.00 to 3.00 feet
Bloom Time: August to September
Bloom Description: White
Sun: Full sun
Water: Medium
Maintenance: Low
Suggested Use: Naturalize
Flower: Showy, Fragrant
Leaf: Fragrant
Attracts: Butterflies
Tolerate: Deer, Drought

Culture

Easily grown in fertile, moist to medium moisture, well-drained soils in full sun. Plants have some drought tolerance, but are less drought tolerant than most of the other species of Pycnanthemum. Performs well in bright shade, but best flowering often occurs in full sun. This plant is a vigorous grower that may spread by rhizomes in optimum conditions, but it is not invasive as are many of the true mints (Mentha). If naturalizing is unwanted, prune roots in spring with a spade to keep clumps from spreading. Propagate by seed or division.

Noteworthy Characteristics

Pycnanthemum setosum, commonly called awned mountain mint, is a rare, clump-forming, herbaceous perennial that typically grows to 1-3’ tall on stiff, slender, square stems clad with ovate to ovate-lanceolate dark green leaves with acuminate tips, toothed to entire margins and rounded bases. Leaves have a mint-like aroma when crushed. This species is native to damp to wet flatwoods, peripheries of wet meadows, forest margins, fields, and clearings in a limited number of sites scattered along the outer coastal plain from New Jersey to Florida and southern Mississippi. Notwithstanding its common name of mountain mint, it does not grow in the mountains.

Plant foliage is topped in mid to late summer by a showy bloom of two-lipped tubular white flowers (each to 1/2" wide) in dense flat-topped terminal (sometimes axillary) clusters, with each cluster being subtended by a pair of leaf-like long-awned bracts. Flowers are attractive to butterflies and bees.

Genus name comes from Greek pyknos meaning dense and anthos meaning flower for its densely packed flowers.

Specific epithet comes from the Latin word setosus meaning full of bristles.

Common name is in reference to the long awns on the flower bracts.

Problems

No serious insect or disease problems. Rust may occur.

Garden Uses

Summer flowers with underlying silver bracts are ornamentally attractive, particularly when grouped or massed. Best when allowed to naturalize in native plant gardens, cottage gardens or meadows. Herb gardens. Border perimeters. Butterfly gardens.