Clustered or short-toothed mountain mint (pycnanthemum muticum) is by far the most popular plant in my yard right now. All day long it is covered in frenzied activity from hungry pollinators. I have more mountain mint flowering than any other kind of plant and wondered if this was impacting the attractiveness of my other natives. Out of curiosity I searched for the most pollinator friendly native plants and there was actually a pollinator trial done at Penn State years ago to determine this. It turns out the top plant was...mountain mint!
Many of the bees on my clustered mountain mint are honey bees. I think one of my neighbors needs to gift me jar of minty honey because the bees commute to my yard in the morning and leave in the evening! This fall I think I'm going to offer local beekeepers mountain mint slips so they can establish a patch. The good news is the existence of so many honey bees is a good sign for the survival of all our local native bees.
Mountain mint more often than not makes its way onto native pollinator nectar and pollen plant lists. The more mountain mint I let ramble through my yard, the more obvious it is that mountain mint is a high value native plant to add to a naturescaped yard for a variety of reasons including:
Mountain mint is easy to grow. It spreads by rhizomes to naturalize and form large colonies. In this case the more the merrier means more pollinators! Most mountain mint species are probably not the best to put in a traditional flower bed or with less vigorous natives. They need their own space to spread or to be planted with other assertive plants like a rhizomatous goldenrod (solidago) or sunflowers (helianthus).
Pycnanthemum, means densely flowered so although mountain mint is not particularly showy, the tightly packed tiny flower clusters on mountain mint offer what seems to be an endless supply of nectar for pollinators, particularly bees, because it flowers for months starting in June.
In the Penn trial, clustered mountain mint (pycnanthemum muticum) tied with stiff goldenrod (solidago rigida) for having the greatest diversity of pollinators visiting it; with bumble bee and small-sized bees the most common bee, and the tachinid fly the most common insect. The wide variety of pollinators I see on my clustered mountain mint supports this finding.
I would suggest specifically seeking out the clustered mountain mint because it is the most vigorous grower and such a pollinator magnet, but there are multiple species of mountain mint to also add to your yard. The following are just a few kinds of mountain I think would grow well in Atlanta because I have them growing in my yard.
Appalachian or Savanna mountain mint (pycnanthemum flexuosum) spreads much slower than other mountain mints and likes moist sunny areas. It might need more sun than I am offering it, but in my small yard, its okay that hasn't taken off after 3 years. The fuzzy white round blooms are the most showy of the mountain mints, but in my yard it is not visited by even a fraction of the pollinators the clustered mountain mint attracts. In addition to being a pollen and nectar source, the reason I have Appalachian mountain mint is because it's a larval host plants for the gray hairstreak butterfly and the wavy-lined emerald moth.
Narrowleaf or slender mountain mint (pycnanthemum tenuifolium) has a delicate look and also doesn’t take over the way the clustered mint does. It seems to tolerate a range of growing conditions. It blooms earlier than the clustered mint so it’s a good plant to add for a longer mountain mint bloom sequence. Its needle-like leaves contrast well with just about any plants nearby.
Whorled mountain mint (pycnanthemum verticillatum) is another mountain mint that spreads by rhizomes, but not aggressively. In my yard it intermingles with other native plants which seems to help support it from flopping over. Whorled mountain mint also seems to be less picky about where it grows and does fine wherever I plant it.
Mountain mint is a great native plant ambassador because most of the species only grow 2-3 feet tall, form attractive patches even when not blooming, and have white flowers that "match" any landscape situation. The clustered mint has particularly pretty silvery leaves and the delicate, wispy narrowleaf mountain mint contrasts well with plants with coarser leaves. The pretty starburst flowers on the Appalachian mountain mint would even be considered attractive in a more traditional garden.
I can’t speak to the health benefits of mountain mint, but there are certain mountain mint species that are used by herbalists in a number of ways, including as an insect repellent. This is funny to me considering how many insects the flowers attract. Although some mountain mint varieties are edible, some such as the clustered mint are toxic, and I’m fine using my non-native culinary mints that I grow in pots on my deck for cooking, and letting the pollinators have all the native mint!
Deer and rabbits don’t like strong smells so they won’t bother mountain mint, making it a perfect addition to a restoration project or in a yard at the edge of a natural area.
Mountain mint can be added to the list of native plants that are great for challenging areas. A friend gifted me some mountain mint to help with erosion control for my right of way strip. It has quickly formed a healthy taller groundcover and offers a blooming welcome mat for pollinators to come to my yard!
Clustered mountain mint is also good choice for a right of way strip where you want an aggressive native to cover the area.
The seed heads of mountain mint are a pretty addition to a winter seedhead garden and add another food source for hungry birds.
I am a big fan of adding common native plants that are easy to grow and offer high value to the ecosystem of a yard, and mountain mint checks all the boxes!