In recent visits to local prairies, I was reminded of a spectacular native plant that is often overshadowed by its more common hybrid cousins.
Wild bergamot (Monarda fistulosa) is a native plant with a home range that spans our continent. It frequents a wide range of locations on the landscape, such as prairies and woodland edges or abandoned pastures and road right-of-ways. This tough plant thrives in bone-dry, full-sun to more mesic and part-shade locations, occupying all but the most wet and poorly drained sites. Yet, in the home landscape, it is often overlooked for the more commonly available cultivars of its close relative, bee balm (Monarda didyma), or hybrids between the two species.
In any discussion of Monarda, it can be important to use Latin names, as the whole genus is frequently referred to as “bee balm.” In total, there have been 17 native Monarda species identified in North America, and the two mentioned here have a long history as sought-after ornamental plants. The first recorded M. didyma in cultivation was noted as early as 1745 in New England, although this plant was valued by Native Americans long before for medicinal uses.
With tufted flowers that sport tube-like petals atop dangly stems, Monardas look like something out of a Dr. Suess book. It’s this spectacular display that makes them one of our showiest summer-blooming perennials.
Pollinators recognize Monarda as something special too, as these plants attract a wide range of insects as well as hummingbirds. Nectaries are located at the base of long, tube-like petals, which does limit nectar access for some pollinators with shorter tongues. Nevertheless, as industrious insects typically do, some have found ways around this.
Mason wasps and bumblebees have both been observed chewing holes through petals to access nectaries on a variety of plant species. In many of these cases, such as with Monarda flowers, smaller short-tongued pollinators, such as sweat bees, have been shown to use access holes chewed by others to get nectar. These interesting workarounds have often lead some of these pollinators to be called thieves, and they inadvertently have avoided contact with pollen-bearing flower parts.
Although flowering displays may be spectacular, Monarda is not a complaint-free group of plants among gardeners. Being a mint family member, they spread by rhizomes and may outcompete less-vigorous neighboring plants. In addition, powdery mildew is a common pathogen on most all Monarda species. Although it’s rarely a plant-health issue, it lowers aesthetic value in late summer.
In recent decades, much of the breeding efforts among Monarda species have been focused on improved powdery-mildew resistance. Although there have been some cultivars of M. didyma released, the vast majority of new plants are hybrids between M. didyma and M. fistulosa. Many of the new hybrids do exhibit good resistance to powdery mildew, although not all live up to what may be expected.
However, there are some basic recommendations to manage powdery mildew that aren’t all that hard to apply. Since this fungal pathogen infects leaves and loves moisture, simply increasing airflow can help drastically. Removal of infect foliage by cutting back after flowering can help reduce poor appearance, improve airflow and promote a new flush of uninfected leaves. As with most all fungal foliage infectors, removing dead leaves on the ground and end-of-season cleanup of infected stems can help to reduce infection next year.
While newer hybrids may address powdery-mildew issues, there are always questions as to whether a hybrid will support pollinators as well as its native parents. I’ve found that M. fistulosa does wonderfully when planted in a mixture of native tall grasses, asters and goldenrods.
The taller neighboring natives serve to hide powdery mildew damage in the late season and limit rambunctiously spreading Monarda. In addition, this type of design is similar to native prairie settings where Monarda occurs naturally. Perhaps mimicking our native plant community is a better overall solution than adding hybrid plants?
If you are interested in seeing wild bergamot in a natural setting, the Champaign Park District has thriving populations at several of its parks, including Heritage Park, Robert C. Porter Family Park and Sunset Ridge park. It’s well worth the visit as each park supports a thriving prairie population!