Plant Preference/Growing Conditions:

Slender Mountain Mint is best grown in full sun to partial sun in average, dry to medium, well-drained soils. They prefer acidic soils. It is also able to tolerate drought, clay, and dry soil. 

Growth Habit/Description:

This mint grows in clonal colonies from skinny, near-surface, branching rhizomes. This herbaceous perennial can grow up to 2-3 ft. tall and sometimes up to 4ft. The way it branches gives the mint a bushy effect. Slender stems are hairless and has slender opposite leaves. Leaves are up to 3" long and 1/4'' across.  Its upper stems bloom with short white tubular flowers, sometimes with small purple dots.  Small dark seeds that can be dispersed by gusts of wind. The mint can spread vegetatively, forming colonies of closely bunched plants. Can aggressively spread but can be controlled easily. The plant spreads quickly through rhizomes and due to that would be good erosion control. 

Bloom Season:

Short white tubular flowers bloom at the end of the upper stems from in late summer from June to July.  

Fall and/or Winter Interest?

Yes. Fall foliage is yellow. It has leafless stems and heads that persist into the next growing season. 

Host Plant for Caterpillars?

Yes. Slender Mountain Mint is the host plant for the Gray Hairstreak Butterfly(Strymon melinus), Regal Frilitary(Speyeria idalia), Delaware Skipper(Anatrytone logan), Wavy-Lined Emerald(Synchlora aerata), Hermit Sphinx(Lintneria eremitus), Curved Tooth Geometer(Eutrapela clemataria), and Tobacco Budworm Moth(Helicoverpa armigera). 

Other Known Ecological Value?

Yes. Deer consume its leaves and numerous animals consumes its seeds. When it's blooming season, it attracts native bees, bumblebees, honey bees, different species of butterflies, and birds as well. 

Origin of Name:  The genus name is based on the Greek word words for "dense" and "flower." Its epithet is from the Latin for "slender leaved."

Related Plant Species: Slender Mountain Mint can be distinguished from other mountain mints by its linear leaves less than 1/4 inch wide and its smooth leaves and stems. There are five other mountain mint species within Arkansas: White-Leaf Mountain Mint (Pycnanthemum albescens), Short-Tooth or Clustered Mountain Mint (P. muticum), Hairy Mountain Mint (P. pilosum), Whorled Mountain Mint (P. verticillatum), and Virginia Mountain Mint (P. viginianum). Out of these five, Whorled Mountain Mint and Virginia Mountain Mint are the most similar to Slender Mountain Mint due to their narrow leaves. The full list of its relatives from the Pycnanthemum genus can be found in this link.

Use For Food/Medicine:

Its leaves can be rubbed on skin to repel mosquitoes. Its leaves was used by the Cherokees as a poultice to treat headache, and internally to treat colds, fever, and upset stomach. Slender Mountain Mint has also been used in herbal teas and many natives tribes as a seasoning in food to improve flavor. 

Arkansas Native Plant Society. Know Your Natives - Slender Mountain Mint [Cited 2023, Sept 8] Available from:

https://anps.org/2021/09/27/know-your-natives-slender-mountain-mint/

McGrady, Doug. Holocombe, Jeff.  Gardenia. Pycnanthemum tenuifolum (Narrowleaf Mountain Mint) [Cited 2023, Sept 8]. Available from:

https://www.gardenia.net/plant/pycnanthemum-tenuifolium 

North Carolina Extension Gardener Plant Toolbox. Pycnanthemum tenuifolum [Cited 2023, Sept 8]. Available from: https://plants.ces.ncsu.edu/plants/pycnanthemum-tenuifolium/ 

Native Plant Trust: Go Botany. Pycnanthemum tenuifolium — narrow-leaved mountain-mint [Cited 2023, Sept 8]. Available from: https://gobotany.nativeplanttrust.org/species/pycnanthemum/tenuifolium/#:~:text=Facts,colds%2C%20fever%20and%20upset%20stomach

Hilty, John. c 2002-2020. Illinois Wildflowers. Slender Mountain Mint [Cited 2023, Sept 8]. Available from: https://www.illinoiswildflowers.info/prairie/plantx/slm_mintx.htm 

Ladybird Johnson Wildflower Center Plant Database. Austin (TX):  University of Texas--Austin. Pycnanthemum tenuifolium [Cited 2023, Sept 8]. Available from: 

https://www.wildflower.org/plants/result.php?id_plant=pyte 

 Northeast Pollinator Plants. Pycnanthemum tenuifolium [Cited 2023, Sept 8]. Available from:

https://www.northeastpollinator.com/products/pycnanthemum-tenufolium 

Prairie Moon Nursery. Pycnanthemum tenuifolium [Cited 2023, Sept 8]. Available from :

https://www.prairiemoon.com/pycnanthemum-tenuifolium-slender-mountain-mint-prairie-moon-nursery.html#:~:text=Slender%20Mountain%20Mint%20grows%20best,especially%20when%20crushed%20or%20cut

North Creek Nurseries. Pycnanthemum tenuifolium [Cited 2023, Sept 15]. Available from:

https://www.northcreeknurseries.com/plantName/Pycnanthemum-tenuifolium 

Bagley Pond Perennials. Slender Mountain Mint - Pycnanthemum tenuifolium [Cited 2023, Sept 15]. Available from:

https://bagleypondperennials.com/products/slender-mountain-mint-pycnanthemum-tenuifolium 

Sheahan, C.M. United States Department of Agriculture: Natural Resources Conservation Service. Narrowleaf Mountainmint (Pycnanthemum tenuifolium) Plant Guide [Cited 2023, Sept 17]. Available from:

https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_pyte.pdf 

Last edited by Alice Dong, September 2023.