For those unfamiliar with the plant, Mountain Mint is a name given to a genus of plants native to North America that are distantly related to your standard garden mint. Their leaves are edible; have a strong, sharp mint-like taste; and can be used to make tea. That said, mountain mints aren't commonly grown for their taste, but instead grown in gardens as companion plants for their ability to attract many pollinators.
All in all, my experiment was successful. The plants germinated successfully and grew very rapidly. This is after about 30 days (Virginia MM on the left, Hairy MM on the right):
I ended up trimming them down since they started getting too tall. The Virginia MM started bushing out a lot as a result. But the Hairy MM has been pretty persistent in its pursuit to grow beyond the Harvest unit.
The plants absorbed almost no nutrients and barely any water, which is why I have a bit of algae buildup. For anyone wanting to repeat this experiment, the nutrient requirements are about the same as lettuce (i.e. very low, maybe around 100-200 ppm).
The plants get very tall. In the photo, it's about ~1 month in. 2 months later and the Hairy MM was about three times the height. I honestly kept the light off to prevent the plant from burning. This is probably an experiment that shouldn't be started in winter, because I have no where to transplant it.
The leaves do have a nice minty taste, but it is much sharper and more aromatic than regular mint.