When, in 1773, American patriots famously dumped 342 chests of tea into Boston Harbor as a political protest, they were left with a dilemma. What could they use to make tea, since the continued consumption of British tea was considered to be unpatriotic? Enter Monarda didyma, a plant used by Native Americans of the Oswego tribe to brew a medicinal hot beverage. Reportedly, many colonists adopted this beverage as substitute for British tea, thus giving the plant one of its common names: Oswego tea. In honor of this attractive, durable plant, the National Garden Bureau has designated monarda as its perennial plant of the year.
Monarda is a genus in the Lamiaceae (or mint) plant family. The latter is a rather large family containing over 200 genera and 7000 species. Most are noted for their aromatic foliage that is the result of essential oils produced by the leaves of the plant. Numerous species in this family are widely used as culinary herbs, or commercially grown for their oils which are used for a variety of purposes.
As a genus, Monarda contains over 20 species, all of which have spicey, fragrant foliage along with lanceolate leaves and square stems.
Monarda species of horticultural importance include:
In recent years, Monarda has been the subject of breeding efforts aimed at improving its garden appearance as well as its resistance to powdery mildew. The latter being its primary disease nemesis. These efforts have resulted in the release of nearly 50 commercial (mostly hybrid) cultivars whose colors range from dark red mahogany to bluish lilac to multiple shades of pink.
For example, 'Marshall's Delight,' is an early improvement of M. didyma and is noted for its bright pink flowers which are produced over an extended period of time. Mature plants achieve a height of only 24-30 inches. These virtues, along with its reported resistance to powdery mildew, earned this cultivar the coveted Award of Merit from the Royal Horticultural Society.
Other relatively early introductions include 'Gardenview Scarlet' which features rose-red tubular flowers borne in dense, terminal heads on plants 24-36 inches tall, and 'Petite Delight,' the first dwarf monarda, which reaches a mature height of only about 12-15 inches and bears lavender-rose flowers.
More recent introductions of monarda are the result of crossing M. didyma with M. fistulosa, resulting in cultivars producing vibrant flower colors on more "well-behaved" plants. Examples include 'Grand Parade'™ which is an exceptionally hardy cultivar characterized by its profuse production of bright lavender-purple flowers atop mid-sized plants that display very good mildew resistance.
The 'Sugar Buzz'® series is relatively new to the gardening world. The series boasts a variety of colors, all bearing flowers that form a solid dome of color on top of 20-inch plants, making them well-suited for planting in the middle of a perennial border. All have strong stems along with deep green foliage that displays above-average powdery mildew resistance.
Finally, the 'Balmy'™ series of monarda have relatively large flowers on compact plants that reach a mature height of only about 10-12 inches. The foliage is deep green, and shows exceptional resistance to powdery mildew. The 'Balmy'™ series is available in four different colors including lilac purple, vivid pink, purple-red and rosy-pink.
While some monarda cultivars can be produced from seeds, most of the newer ones must be vegetatively propagated, since they are inter-specific hybrids. As a rule, monarda is easy to care for and prefers full-sun to light shade exposures, in gardens soils that are well-drained and relatively high in organic matter. Keep soil uniformly moist throughout the growing season and mulch to conserve moisture and discourage weeds. Try to locate monarda in a spot with good air circulation to lessen powdery mildew infestation.
In the Midwest, monarda plants will die back to the ground during winter, after which they can be cut back to allow one to two inches of stem. Additionally, the removal of dead leaves is advisable, especially if powdery mildew was problematic during the previous growing season.
As monardas emerge in the spring, plants may be pinched to create a bushier growth habit, if desired. A light application of a balance fertilizer at the time of spring emergence also is advisable. In full sun, monardas will produce an abundance of brilliant flowers beginning in mid-summer. As flowers fade, deadheading can help to encourage additional flowering.
Monardas are extremely attractive to pollinating insects such as bees and butterflies, as well as to hummingbirds. In contrast, they seem to resist attacks by deer and rabbits fairly well. Other than the afore-mentioned powdery mildew, they are relatively pest free.
Whether planted en masse in naturalized areas or as specimen plants in perennial borders, monardas are real "show stoppers' when in full bloom. Additionally, they bring a lot of charm and interest to the garden when inter-planted with other perennials such as yarrow, hyssop, daylily or garden phlox, for a continuous display of garden color into the fall.
Credit: Adapted from article by the National Garden Bureau.
REVISED: April 2, 2021