Culture
Easily grown in fertile, moist to medium moisture, well-drained soils in full sun to part shade. Plants 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 muticum, commonly called mountain mint or short-toothed mountain mint or clustered mountain mint, is a clump-forming aromatic perennial that typically grows 1-3’ tall. It is native to Eastern North America (Maine to Michigan to Illinois and Missouri south to Florida and Texas) where it typically grows in grassy open places, meadows, fields, low woodland areas and occasionally in dry upland woods, but not in alpine areas as somewhat inaccurately suggested by its common name. In Missouri, it is only found in the far southeastern corner of the State.
This densely leaved mountain mint features dark green leaves which have a strong mint-like (spearmint) aroma when crushed. Branched stems (mostly square in cross section) are clad with nearly sessile, ovate to ovate-lanceolate, acuminate (pointed), dark green leaves (to 2 1/4" long) with round to heart-shaped bases and toothed margins. Plant foliage is topped in mid to late summer by a bloom of two-lipped tubular pink flowers (each to 1/2" wide) in dense flat-topped terminal (sometimes axillary) clusters, with each cluster being subtended and highlighted by a pair of unique and showy silvery fringeless leaf-like bracts located near the base of the cluster. When planted in groups or massed, the silvery bracts give the entire planting the appearance of being dusted by a white powdery snow. Flowers are attractive to butterflies and bees.
Leaves can be used to make mild tea. Native Americans used this plant for treatment of fevers, colds, stomach aches, and other minor physical ailments.
Genus name comes from Greek pyknos meaning dense and anthos meaning flower for its densely packed flowers.
Specific epithet comes from the Latin word muticus meaning blunt.
Problems
No serious insect or disease problems. Rust may occur.
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.