Tuesday, September 3, 2019

Some Forgotten Native Mints

The Mints, Lamiaceae, are a large family of plants with about 40 genera appearing in eastern North America.  Native species that we commonly think of used as landscape plants include Beebalms (Monarda), Mountain mints (Pycnanthemum), giant hyssop (Agastache), Salvias and Obedient plants (Physostegia).  There are also the non-native species commonly used a culinary herbs like  thyme, oregano and the spearmint.  Common attributes of mints include tubular bilabiate (having two lips) flowers usually occurring in whorls or dense spikes, square stems and often aromatic foliage.  I recently wrote about the mountain mints that I have been growing and it got me to thinking of some of the smaller and less common (in the garden) native mints.

Here you can see the dense flower cluster of wild basil.   Blooming
continues from these throughout the summer months.

One of the wild mints that always surprises me when I spot it in the meadow is wild basil, Clinopodium vulgare, (formerly Satureja vulgaris).  Although the leaves and flowers are essentially unscented, this is made up for by the  clusters of pink flowers appear scattered throughout the tall grasses.  The stems are not particularly stiff, but they lean up against the taller grasses and meadow perennials like ironweed and wingstem (Verbesina alternafolia) allowing the flowers to reach up to 3 or 4 feet into the meadow matrix.  My plants bloom sporadically throughout the summer months.  I've also seen this plant growing alone in shady sites.  Without taller plants to lean on it grows about a foot tall on lax stems.
Here is some wild basil that is growing in shade and had been surround, until recently,
by Japanese stiltgrass. Note how the stems are reachng out to find more light.

The native range of wild basil is from eastern Canada to Tennessee and North Carolina.  Outside of that area plants are likely introductions from Europe.  On-line suppliers of native seed include Toadshade Farm and Prairie Moon Nursery (as Satureja vulgaris).

Pictured here is self-heal blooming in mid-July.  The flowering
 stalk grows from about 4 inches to a foot in height.
Self-heal or Heal-all, Prunella vulgaris, is found throughout the Northern hemisphere.  The North American variety (var. lanceolata) has somewhat narrower leaves than its European relative, which is also found scattered through the eastern parts of North America.  This perennial overwinters as a low mat of leaves that push up flowering stalks, 6-10 inches in mid-summer.  In my opinion these wouldn't work as a ground cover on their own, since they are attractive for only a few weeks to a month in summer.  But they would be a useful component in a mixed ground cover including violets, low sedges, spring ephemerals and the like.  One year it was growing densely in the vegetable garden so I thought I would treat it as a green mulch around some tomatoes.  Turns out the tomatoes did not do well surrounded by self heal.  I guess that there was too much competition and the tomatoes lost out.  
This plant is edible and can be added to salads.
  Among its uses as an herbal remedy treatment of wounds and infections of the throat.   It is attractive to bees and butterflies and is a host plant for the clouded sulfur butterfly.  Seeds are available from several sources found on-line.  To get the North American variety you may need to check  and verify with the supplier where the seed is from. 

Here is Meehan's mint (circled) growing in dry shade.  Also present here
 are Virginia creeper (good) and Vinca minor (bad).  

Meehan's mint, Meehania cordata, is native to the Appalachian Mountains from western Pennsylvania to Tennessee and North Carolina.  It grows well in shady moist areas as a trailing vine that roots where leaf nodes contact the soil.  It can also handle dry shade, though it will be less vigorous.  In general appearance it is similar to the weedy invasive, ground ivy, Glechoma hederacea.  Meehan's mint has slightly larger and stiffer foliage and has no scent when crushed, unlike ground ivy.  Under favorable conditions it blooms in late spring with clusters of  inch long lavender blue flowers held on 6 inch long stems.  In this respect the floral display of Meehan's mint surpasses that of ground ivy.  It is recommended as a native substitute for exotic ground covers like ajuga and lamiums.
Mine is growing in dry shade and has not bloomed yet.  Follow this link to see it in bloom. When getting it established one needs to be careful about not confusing it with other similar, but non-native species like ground ivy and ajugas.  You can find Meehan's mint at nurseries specializing in native species or on-line nurseries, such as Izel Plants.