Bee balm (Monarda), also known as horsemint, is an herbaceous perennial grown for its fragrant flowers and culinary uses. Gardeners describe the plant's aroma as minty with citrus undertones and often use the foliage and flowers in herbal teas and salads. Bee balm produces showy blossoms in shades of white, pink, purple or red, which rise above the foliage during summer and fall. Plants reach up to 18 inches in height and attract bees, butterflies and other beneficial insects to the garden. Hardy in zones 4 through 9, bee balm thrives throughout most of the United States.
Site and Soil
Bee balm performs best when grown in full sun. The plant tolerates partial shade but may not flower as abundantly and becomes more susceptible to fungal diseases. Bee balm prefers moist, well-drained sandy soil with good moisture retention, though it tolerates dry soil for short periods. For the best results, spread a 1/2-inch layer of organic compost over the planting site each spring to improve moisture retention and fertility. Bee balm spreads rapidly and should be spaced at least 24 to 36 inches from other plantings to allow enough room for its mature size.
An even supply of moisture throughout the spring, summer and fall ensures bee balm's best performance. A deep, thorough watering once every seven to 10 days typically provides adequate moisture, though more frequent watering may be required during periods of extreme heat or drought. Soaking the soil to a depth of at least 6 inches at each application provides the plant's roots with adequate water. Applying a 2- to 3-inch layer of mulch to the soil surrounding bee balm plants helps conserve moisture and may decrease watering frequency.
Bee balm is not a heavy feeder and doesn't require much supplemental fertilization. Feeding with a balanced 10-10-10 NPK garden fertilizer once per year in early spring typically provides the plant with enough nutrients to grow all season. Frequent or heavy fertilization encourages rampant growth and may increase the severity of fungal diseases such as powdery mildew. Spreading organic compost around the plant just after planting and each spring thereafter also helps naturally increase the nutrients in the soil without over-feeding.
Deadheading and Pruning
The removal of spent flowers, known as deadheading, prolongs the blooming season and encourages the formation of new blossoms. Removing the flowers as close to the stem as possible increases visual appeal and reduces the risk of disease. Flowers may also be removed for display or drying when in full bloom. Snip off individual leaves and flowers any time during the growing season for adding to salads or making herbal tea. If leaves are regularly harvested, bee balm requires little pruning. Only prune the plant if it begins to grow in an undesired direction. As bee balm spreads rapidly, be prepared to pull up unwanted sprouts in spring and summer.
Propagation and Division
Propagating bee balm by seed or division produces the best results. Sow seeds indoors about eight weeks before the last spring frost and transplant into the garden about one week before the last frost. Because it spreads very quickly through its system of underground stems, bee balm requires dividing once every two or three years to rejuvenate the plant and control its spread. Dividing during early spring ensures the least amount of damage to plants. Dig up plants and divide each root clump into sections using a sharp knife, with each section containing two or three shoots and its own root system. Replant the new bee balm plants immediately and resume regular care.