Pycnanthemum muticum: Clustered Mountain Mint

Latin name:  Pycnanthemum muticum
Common name: Clustered Mountain Mint
Flowers: Greenish-white with gray bracts mid to Late summer ⁴, 1/2" wide ¹²
Fruit or cones: Inconspicuous nut ⁴
Height & Width:18-36 in ⁴
Type: Herbaceous perennial ¹²
Habit: Spreading clump ¹²
Wetland indicator category**: ¹⁷

Atlantic and Gulf Coastal Plain	FAC
Eastern Mountains and Piedmont	FAC
Great Plains	UPL
Midwest	FAC
Northcentral & Northeast	FAC

Texture:  Medium ¹²
Growth rate:  Fast ¹²
Light:  Full sun to part shade ¹²
Moisture:  Average- moist ⁴
Soil*: Clay-sandy loam, neutral/slightly acidic PH ¹²
Zones:  USDA Zones 4-8 ¹²
Origin:  Native L48 ¹⁶
Ecosystem benefits: Food, nectar and pollen, larval food source¹²

Features:  Smells like peppermint ⁴. The plant grows quickly and can grow in shallow soil with bright- partial sun depending on flower preference. Rabbits and deer avoid this plant because of the strong scent. Since this is an herb, it can be used in tea. Blooms 4-6 weeks with full sun ¹².

Siting:  Naturally found in sunny openings where the forest has been cleared or soil is shallow ¹². Pycnanthemum muticum can grow in part shade, but it does not flower as well as full sun ¹². Can be made to look like a bush for yards ¹².

Care: Plant crown at soil level ¹⁸. At planting, water the roots and surrounding area slowly and deeply. Keep soil moist until plant is established, then apply enough water to thoroughly moisten the root zone when the soil is dry or during drought. Modify water recommendations to reflect site drainage and rainfall. Apply 3” of mulch over the planted area. Do not allow mulch to touch the plant stems ¹⁸.

Pests: Plants are relatively pest resistant if cultural preferences are met ¹².

This plant does not appear on the following invasive plant lists on (9/24/2022):

• X USDA SC Invasive Plant Species Web site at http://www.invasivespeciesinfo.gov/plants/main.shtml
• X SC Exotic Plant Pest Council Web site at http://www.se-eppc.org/southcarolina/

Author: Chloe Aiello

Image source: NC State. “Pycnanthemum Muticum.” Pycnanthemum (Mountain Mint) | North Carolina Extension Gardener Plant Toolbox, 2022, https://plants.ces.ncsu.edu/plants/pycnanthemum/.

Sources:

1. Armitage, A. (2001). Armitage’s manual of annuals, biennials, and half-hardy perennials. Portland, OR: Timber Press.
2. Armitage, A. (2006). Armitage’s native plants for North American gardens. Portland, Oregon: Timber Press.
3. Armitage, A. (2008). Herbaceous perennial plants: A treatise on their identification, culture, and garden attributes. Athens, GA: University of Georgia.
4. Clemson Cooperative Extension Home and Garden Information Center.(2011). Flowers fact sheets. Retrieved from https://hgic.clemson.edu/category/flowers/
5. Clemson Cooperative Extension Home and Garden Information Center.(2011). Groundcovers & vines fact sheets. Retrieved from https://hgic.clemson.edu/category/groundcovers/
6. Clemson Cooperative Extension Home and Garden Information Center.(2011). Trees. Retrieved from https://hgic.clemson.edu/category/trees/
7. Clemson Cooperative Extension Home and Garden Information Center.(2011). Shrubs. Retrieved from https://hgic.clemson.edu/category/shrubs/
8. Dirr, M. A. (2009). Manual of woody landscape plants. Champaign, IL: Stipes Publishing.
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11. McMillan, P., Plant taxonomist Clemson University, personal communication.
12. Missouri Botanical Garden Kemper Center for Home Gardening. Plant finder. Retrieved from http://www.mobot.org/gardeninghelp/plantfinder/Alpha.asp
13. North Carolina State University (2005). Plant fact sheets. Retrieved from http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/index.html
14. Strother, E. V., Ham, D. L., Gilland, L. (2003) Urban tree species guide: Choosing the right tree for the right place.  Columbia, SC: South Carolina Forestry Commission.
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16. USDA . Plant profile. (n/d).Retrieved from http://plants.usda.gov/java/
17. USDA. Plant wetland indicator status. (n/d). Retrieved from http://plants.usda.gov/wetland.html
18. Vincent, E., Environmental horticulturist Clemson University, personal communication.
19. Clemson Extension. Carolina Yards Plant Database. Retrieved from https://www.clemson.edu/extension/carolinayards/plant-database/index.htm

*Soil pH is determined using a professional soil test. Contact your Clemson University County Extension service for assistance www.clemson.edu/extension/. Click on “local offices”.

**2012 Plant Wetland Indicator categories (quantitative derived) http://plants.usda.gov/wetinfo.html

 

Indicator Code	Indicator Status	Comment
OBL	Obligate Wetland	Almost always is a hydrophyte, rarely in uplands
FACW	Facultative Wetland	Usually is a hydrophyte but occasionally found in uplands
FAC	Facultative	Commonly occurs as either a hydrophyte or non-hydrophyte
FACU	Facultative Upland	Occasionally is a hydrophyte but usually occurs in uplands
UPL	Obligate Upland	Rarely is a hydrophyte, almost always in uplands