Pycnanthemum muticum

I recall my first encounter with a patch of blunt mountain mint in a private garden in North Carolina many years ago. Seared into my memory was the amazing silver patina of this plant, as seen from the distance (“What the heck is that!?”) and then upon closer inspection, the sheer number and diversity of enthusiastic pollinators was staggering. This patch was literally “abuzz” with activity. Native to a large portion of eastern North America, the blunt mountain mint (Pycnanthemum muticum) is hardy in Zones 4-8 and is a mint family (Lamiaceae) member that while vigorous, isn’t a plant you regret planting particularly if you commit to a bit of vigilance and gentle guidance.

Easily grown in full sun or part shade in a wide range of moist, but well drained, fertile soils, this robust grower reaches 36 inches in height and spreads by shallow rhizomes. Clay soils are acceptable and Pycnanthemum muticum is drought tolerant once established. Root/rhizome pruning with a sharp spade in spring can keep clumps from spreading beyond the desired, dedicated “real estate.” The foliage (oval, toothed leaves) has the fresh scent of peppermint and leaves are arranged on strong, square, branched stems. Blooming from July through September, the clustered, tiny white to lavender, tubular, two-lipped flowers are pollinator magnets. Closest to each inflorescence, the silvery-white bracts offer an interesting white patina to the upper portion of the plant. To top it off, this plant is also deer and rabbit resistant with few other pests or disease issues.

I recently ran across results from a pollinator trial done by Penn State Extension in 2013 in which 88 herbaceous, pollinator-friendly perennials were evaluated for pollinator value. Blunt mountain mint was No. 1 for flowering duration (10 weeks), No. 1 for most pollinator visitor diversity, No. 1 for sheer number of insect visitors and No. 1 for sheer number of bee and syrphid (hoverfly) visitors. This perennial is on most Top 10 lists for pollinator value and has the hardiness, durability and ornamentality to appeal to a wide range of the gardening public.

Specifics

Name: Pycnanthemum muticum

Common name: clustered mountain mint, blunt mountain mint, short-toothed mountain mint

Description: This branching, colonizing perennial, reaching 36 inches tall, features fragrant foliage and clusters of nectar-rich, small tubular flowers hovering above showy, silvery bracts.

Hardiness: USDA Zones 4-8

In the landscape: This perennial is best used in situations where it is allowed to create an expanding, naturalized cluster or drift with other stalwart perennials surrounding it. Blunt mountain mint is a prime candidate for a pollinator garden, native plant garden and/or rain garden. Control and dictate the desired expansion/spread.