Spotted Horsemint (Monarda punctata): A Beauty with Many Names
Jim Lakin, MD Master Gardener
Are you looking for a good low-maintenance plant for a prairie, pollinator, native or butterfly garden? Consider Spotted Horsemint. This native is valuable to pollinators as it attracts butterflies, moths and hummingbirds. It is a great source of nutrients to a number of native specialist bees. It will look great in your garden as a border or mass planting.
It seems like the prettier and more agreeable the plant the more names it collects. This is certainly true of Monarda punctata. She’s called Dotted or Spotted Horsemint, Dotted or Spotted Bee Balm or sometimes just Bee Balm to be confused with true Bee Balm (Monarda fistulosa) that we talked about last month. I point this out not just to prove that Linnaeus was right to assign unpronounceable Latin names to everything that grows. To make certain you’re getting the right plant, be sure to select Monarda punctata when you are looking for spotted horsemint in your local nursery or seed catalogue. When you do get the real thing, you’ll be acquiring a hardy perennial herbaceous that is native to Eastern and Central North America all the way up to Zone 3a. This should tell you it’s a pretty tough customer in addition to being a showy addition to your summer garden.
From July through September, it produces yellowish to purple-spotted 3-to-6-inch flowers in whorls on a densely packed elongated spike. Below the flowers, large, purplish leaf-like bracts set off the arrangement.
Being a member of the mint family Lamiaceae, spotted horsemint puts out runners to form fairly large clumps if left to its own devices. It is not considered to be too aggressive, however. Plants tend to grow to about 1 to 2 feet, occasionally taller. You should space them out by 12 to 24 inches when planting. It is important to allow for air circulation among the plants as they are susceptible to powdery mildew and rust. However, this usually occurs late in the season after flowering. If it is a cosmetic problem, prune the affected stems.
Spotted horsemint likes full sun but will put up with part shade (direct sunlight for 2-6 hours per day). It does best in loam, silt or sandy soil which can be an issue here in our clay-ridden Minnesota soil, although I’ve not found that to be too great a problem with Monarda. As you would expect, it is found in the wild in prairies, sandy areas, rocky woodlands and coastal plains. It will even self-seed in almost pure sand. The prairie strains at least are fairly drought resistant.
Spotted horsemint is of substantial value to the native wildlife attracting a plethora of butterflies, moths and hummingbirds. It is a great source of nutrients to a number of native specialist bees. Happily, it is not a valuable food source for deer or rabbits who tend to leave it alone unless things are getting desperate.
So, if you are looking for a good low-maintenance plant for a prairie, pollinator, native or butterfly garden consider spotted horsemint. As a border or a mass planting, it does great!