The Southside Master Gardener Association (SSMGA) supports the Virginia Cooperative Extension and its mission to “enable people to improve their lives through an educational process that uses scientific knowledge focused on issues and needs”.
A Prodigious Pollinator Powerhouse
by K. Bagby, VCE Southside Master Gardener, Virginia Master Naturalist Southern Piedmont Chapter
Just recently at the Halifax Farmers Market, Kathy Cornell had some slips of mountain mint that she gave away. That might not sound like much but –
Mountain mint, Pycnanthemum species, is a pollinator treasure. It’s truly a hard-hitting generalist. A study conducted several years ago by Penn State Master Gardeners and the Penn State Southeast Agricultural Research and Extension center involved planting 4,500 plant plugs from 85 species and cultivars of native plants. They counted 72 species of bees, wasps, syrphid flies—the hover flies and flower flies—and tachinid flies among the visiting pollinators, a diverse array of insects. Hands down, the mountain mint attracted more pollinators than any of the other plants. Second place went to Solidago, the goldenrods, but it wasn’t even close.
About a dozen species of mountain mint are found in Virginia. Not to be confused with true mints such as spearmint or peppermint! Though both types of mint are members of the Lamiaceae family, mountain mints belong to the Pycnanthemum genus, while the members of the Mentha genus include the aforementioned spearmint and peppermint as well as basil, rosemary, sage, oregano, catnip, and lavender.
One of the biggest differences between the Pycnanthemums and the Menthas is that the former are natives, and the latter are not, though some of them have naturalized over the years. What does this actually mean?
The simplest answer is that native birds, insects, and animals do best on the native plants they’ve co-evolved with over the centuries. But behind that simple answer lies the complexity of the food web that sustains us all: too deep a subject for this short article. Just remember that song about the toe bone connecting to the foot bone, and the foot bone connecting to the knee bone, and then the hip bone and backbone and everything else. Well, that’s the food web: it’s all connected. Pull one element out and you risk collapsing the whole structure.
Food webs aside, being cousins, mountain mints and true mints have a lot in common, including the classic square stems. Both are aromatic, though the true mints are usually more so. The leaves can vary quite a bit, but the mountain mints usually feel velvety and have a whitish bloom, which can be striking in mass plantings. Possibly the most important difference for home gardeners is that while mountain mints spread by rhizome, as do the true mints, they’re far less aggressive than the true mints, and they’re easier to pull up to tame the plant’s growth. No worries about mountain mint taking over your whole garden!
Mountain mint generally prefers full sun to part shade. It can tolerate different types of soil, but it needs good drainage to prevent root rot. You can divide or plant in spring or fall before the temperatures get too hot or cold. If you’re starting with seeds, sow them on the surface of the soil then just barely cover them with soil—they need sunlight to germinate.
As with many natives, mountain mints are reasonably drought-tolerant and deer-resistant, though consider watering if it’s hot and dry for an extended period. You don’t need to fertilize them. Cut them back in late winter or early spring if you’d like. One of their best characteristics is a long blooming period starting in late summer and extending into the fall—perfect for pollinators that have lost spring and summer blooms and need something to eat. Deadheading spent flowers can help extend that blooming period.
So there’s a very short introduction to a powerhouse native plant. Hopefully you managed to get one of Kathy’s slips! Flora of Virginia has great information on our local mountain mint species, and https://plants.ces.ncsu.edu is always a great source of information.
Many thanks to our Virginia Cooperative Extension Southside Master Gardeners and Virginia Master Naturalist Southern Piedmont Chapter, and to all the people who give their time to and through these groups to serve their communities. Many, many more thanks to our late mentor and friend, Bill McCaleb.
The Virginia Cooperative Extension Halifax Office is open from 8 a.m. to 5 p.m. Monday-Friday. If you have gardening questions, you can reach an extension master gardener or extension staff member by sending an email to ask@ssmga.org or by calling the Halifax Extension Master Gardener Help Desk at 434-830-3383. Be sure to give us your first and last name, telephone number and the nature of the call. The help desk phone is routinely checked Monday-Friday. Someone will get back to you, although it may be from a different telephone number.
Happy gardening!
