Narrow leaf mountain mint Pycnanthemum tenuifolium

Narrow leaf Mountain Mint - Pycnanthemum tenuifolium

If you have experience growing any of the mountain mints, we would like your opinion. Let us know how it performed in your butterfly garden. Your comments will help other butterfly gardeners in your region to create better butterfly gardens:

As the name implies, the mountain mints belong to the mint family (Lamiaceae). These plants increase in size by sending out underground stems (called rhizomes). While some gardeners enjoy growing a plant that increases in size each year, in some situations, mountain mints may seem invasive and will need to have new shoots pulled each year.

Mountain Mints - Pycnanthemum species

NABA member Mary Anne Borge shares the following report about mountain mints located in southern New Jersey:


Mountain mints are in bloom right now , and they are covered with a spectacular variety of butterflies, bees, wasps, and moths!  These beneficial pollinators all graze for nectar Mountain Mint Pycnanthemum muticumcontentedly, since these plants provide enough food for everyone simultaneously, and over a long period of time.  From morning until evening these plants are alive with the dance of the pollinators.  


The bloom period begins in July, and extends at least through August.  Like other members of the mint family, these species have clusters of flowers that bloom progressively over a long period of time. 


There are several species of mountain mint, but my favorites are short-toothed mountain mint (Pycnanthemum muticum) and hoary mountain mint (Pycnanthemum incanum).  The genus name, Pycnanthemum, means densely flowered, hinting at the reason that these plants can accommodate so many hungry visitors simultaneously.  The foliage of these two species is as showy as the flowers, extending the period of visual appeal. 


Short-toothed mountain mint grows to a height of about 2-3 feet, topped with round heads of tiny white flowers smudged with bright magenta.  The plants are truly ‘densely flowered’.  The flowers are set off by the leaves that frame them, which a powdery pale blue-green with a velvety looking texture.  Rub or crush the leaves and you’ll be rewarded with a sent that confirms that this is a mint family member.  After the long bloom period, the flower heads dry to an eye-catching dark gray, making it an attractive plant throughout the winter.    Pycnanthemum muticum


Short-toothed mountain mint can tolerate part shade to full sun, and likes moist but well-drained, average soil.  In this photo, an Eastern-Tailed Blue is stopping for a long drink.


Hoary mountain mint, as the name implies, has foliage very similar to short-toothed mountain mint, with the leaves just below the flower heads looking as if they had been lightly but evenly dusted with powdered sugar. Pycnantemum incanum The flowers grow in rounded heads much like Short-toothed mountain mint, but the flowers are somewhat larger.  Each delicate flower is white with a sprinkling of tiny purple spots.  The flowers generally grow in multiple tiers on each stem, with a branching habit that is open and graceful, showing off the additional layers of flowers.  An Olive Hairstreak is enjoying this lovely plant’s offerings.


This species also grows to a height of 2-3 feet, prefers sun, and average to dry soil.


The mountain mints may be a gardeners’ dream come true – attractive, easy to grow, and they are deer resistant! [End of Mary Anne's text]


While the different species of mountain mint can be difficult to tell apart, they are all good garden plants and are worth seeking out. Mountain mints are suggested as an alternative garden plant to the (non-native) invasive oxeye daisy (Leucanthemum vulgare) which is an aggressively spreading plant that decreases native plant diversity where it takes hold.

There are over 20 native species of mountain mint in the United States. The following commonly are used in butterfly gardens and are often found for sale in native plant nurseries: