I love plant swaps and gardening listservs. It’s so much fun to share plants you need to divide, and to acquire new plants to try.
This week I came into two containers of mountain mint, Pycnanthemum sp. I don’t know what species I have, but I suspect it may be Pycnanthemum muticum, or short-toothed mountain mint. It’s about 3 feet tall, with silvery, slightly serrated leaves an inch to an inch and a half long. Small, buttonlike bracts just above the leaves hold the flowers, which are white, I understand. The plant had finished flowering when I acquired it. It smells pungently of mint–much stronger than the culinary mint I grow in containers–and is attractive to bees and butterflies. It is actually more closely related to the Monardas than the Menthas, and the resemblance between their respective leaves and bracts is quite plain.
The woman who shared it with me warned me that it might be another to keep in a container, because it took over her own backyard (classic behavior of both Menthas and Monardas). Her soil is much nicer than mine, though; fluffy and rich, if the material in the pot is anything to go by. I am wary of the possibility of swapping one assertive species for another, but I planted it in the back of the garden where the heavy rains this year have made the English ivy encroaching from the carrot lady‘s yard go berserk. The soil there is positively unimproved, so if the mountain mint shows signs of thriving, I may dig it up and replant it in a sunken container with the bottom cut out.
Bring on the butterflies and bees!