Wednesday, September 18, 2013

Blunt Mountain Mint

Let me tell you about an amazing plant I've had growing for a couple years. I learned a lot about this plant in my research for this post. So what is it? It is called Blunt Mountain Mint (Pycnanthemum muticum), also known as Short Toothed Mountain Mint, Clustered Mountain Mint and Big Leaf Mountain Mint. While Mountain Mint is in the Lamiaceae family with other mints like spearmint and peppermint, it is not a true mint. You wouldn't think that if you crushed some and smelled it though. This native hardy perennial deserves a spot in your garden.

Lets break down its Latin / Greek name. Pycnanthemum is Greek for "dense flower", pyknos = dense and anthos = flower. Muticum is Latin for blunt, referring to the flat leaves at the end of the stems. It was given this name by the French Botanist Andre Michaux when he "discovered" the plant in Pennsylvania in 1790. He named it this because of its tiny densely clustered flower heads. Mine is still flowering a bit, you can see the tiny pinkish flowers on the edges of the heads. Every bump you see on the head had a flower on it recently. 

Insects are drawn to this plant in amazing quantities and diversity. Bees absolutely love it, so do butterflies, wasps, moths and flies. Predators like to hang out on it to ambush nectar enamored insects. The dried heads last through the winter and provide habitat for insects. So make sure you leave them up through the winter.

The leaves contain an organic compound called pulegone, the same chemical in pennyroyal that is used as an insect repellant. For all my chemically inclined readers here is a pretty picture.

File:Pulegone Structural Formulae.png

You can pick some leaves and rub them on exposed skin to keep those pesky mosquito's at bay. Some people have a reaction to this so test a small area of skin before you go all out. The toxicology for humans seems to be largely not researched. A study in rats has shown the chemical pulegone to be toxic in large quantities. Personally I chew a leaf every time I walk by it. So far so good. Do your own research if you are worried about toxicity. Here is an article on the toxicity and myths of pennyroyal, which has higher levels of pulegone than Blunt Mountain Mint. At any rate you would have to eat a lot of this plant to get a large dose of pulegone. Just to be safe, I will state; you should not use this plant if you are pregnant. I encourage you to read the article on toxicity and myths above.

Here is an experiment I hope to perform soon. I will take three crushed leaves of blunt mountain mint and drop them in a glass cylinder filled with frozen water molecules (ice). To this I will add one part ethanol (sky vodka should do the trick) to two parts quinine laced carbonated water (Canada dry will work nicely) and stir. This experiment may need to be repeated several times before I can give any conclusive data.

How would you like to find a use for those old unmatched socks hanging around? Take said sock, put some leaves and flower heads in it and tie the end off. Throw this is your dryer for a fresh minty scent. You can also take some leaves and flower heads and put them in a cheesecloth bag. Tie off the cheesecloth and let this soak in a hot bath. You can use the plant for making potpourri or just place some leaves in your dresser drawers to keep insects away and freshen them up.

I highly recommend growing this plant if you want to bring in pollinators, especially if you keep bees on your property.


  1. Is it a spreader? As you know, I have way too much mint around.

  2. Hey Mike,

    No it does not spread like a true mint does. It pretty much stays where you put it. I think it has pushed out about 4-6 inches in two years. I will try to get a plant if I can do a split.