In July and August, the attractive flowers of bee balm (Monarda) are a common sight in gardens, along roadsides, and in prairies. The flowers are produced atop 2- to 4-foot-tall plants. The 1 1/2- to 3-inch-wide flower heads are composed of slender, tubular flowers. Flower colors include white, pink, red, lavender, and purple.
Bee balm is a member of the mint family. Like most other plants in the mint family, bee balm has square stems, opposite leaves, and is aromatic. Bee balm foliage has a mint-like aroma and is used in herbal teas, salads, and as garnishes. The flowers are also edible.
Bee balm attracts bees (hence the common name), butterflies, and hummingbirds. Other common names include bergamont, horsemint, and Oswego tea.
Bee balms are relatively easy to grow when given the proper site and care.
Bee balms perform best in full sun. While plants tolerate partial shade, they won't flower as heavily and are more susceptible to powdery mildew. They also prefer moist, well-drained soils.
Bee balms like an even supply of moisture during the growing season. For best performance, water bee balms every 7 to 10 days during dry periods. When watering, soak the soil to a depth of 6 to 8 inches. Applying a mulch around the plants will help to conserve soil moisture and reduce the frequency of watering.
Bee balms don't require frequent or heavy fertilizer applications. Sprinkling a small amount of an all-purpose garden fertilizer, such as 10-10-10, around each plant in early spring is usually sufficient. Avoid over fertilization. Frequent or heavy applications of fertilizer will encourage rampant, succulent growth and may increase the severity of powdery mildew.
Prompt removal of the spent flower heads will prolong the bloom period.
Bee balms spread rapidly via underground stems or stolons. In addition, the centers of the clumps often die out within a few years. To control their spread and rejuvenate the plants, it's usually necessary to dig and divide bee balms every 2 to 3 years. Early spring is the best time to dig and divide bee balms. Dig up the plants as soon as they emerge from the ground. Divide the clump into sections with a sharp knife. Each section should have at least 2 or 3 shoots and a good root system. Replant immediately.
Insect and Disease Problems
Bee balms may occasionally suffer some minor insect damage. However, powdery mildew is a more serious problem. Powdery mildew is a fungal disease. It appears as a grayish white "powder" on the upper leaf surfaces. Severely infected leaves drop prematurely. Disease symptoms are most severe on overcrowded plants, those growing in partial to heavy shade, and drought stressed plants.
Cultural practices can reduce the severity of powdery mildew. When planting bee balms, select a site in full sun and space plants 1 1/2 to 2 feet apart. Divide plants every 2 to 3 years and water during dry periods. Remove and destroy disease-infested plant debris in the fall. The fungal spores of powdery mildew survive the winter on disease-infested plant debris. The removal and destruction of this material removes the source of next year's infection.
The best way for home gardeners to avoid the annoying problem of powdery mildew is to select mildew resistant varieties. Varieties that possess good mildew resistance include 'Marshall's Delight' (bright pink flowers), 'Gardenview Scarlet' (scarlet-red flowers), 'Violet Queen' (violet-blue flowers), 'Raspberry Wine'(wine-red flowers), and 'Colrain Red' (purplish red flowers).
Most of the commonly grown bee balm cultivars grow 2 1/2 to 4 feet tall. However, there are a few dwarf cultivars. 'Petite Wonder' (pink flowers) and Petite 'Delight' (rose pink flowers) grow 10 and 15 inches tall, respectively. Powdery mildew resistance for both varieties is fair to good.
When sited properly and given good care, bee balm is a wonderful, easy-to-grow perennial for the home landscape.