Bee balm (Monarda spp.), also known as Oswego tea and horsemint, is a beloved garden plant cherished for its vibrant, often tubular flowers that attract a host of pollinators. Proper winter care is important for its continued health and vigorous return each spring.
Bee Balm’s Winter Hardiness
Bee balm is a resilient perennial, hardy across USDA Zones 3 through 9. This plant naturally enters dormancy as winter approaches. During this period, the visible top growth dies back, but its root system remains alive underground. This natural cycle allows bee balm to conserve energy, ensuring its survival and return when warmer weather returns.
Pre-Winter Preparations for In-Ground Plants
To prepare in-ground bee balm for winter, prune back the foliage after the first hard frost in late fall or early winter. Stems can be cut to about 2 to 4 inches above the ground. This helps prevent overwintering fungal spores, like powdery mildew, and encourages fresh growth in spring. Some gardeners leave dried stalks standing throughout winter, as seed heads provide a food source for birds and offer visual interest.
Before the ground freezes solid, especially if autumn has been dry, deep watering is important. This ensures the root system is hydrated, which aids cold tolerance through winter. Apply a 2 to 4-inch layer of organic mulch, such as shredded bark, compost, or straw, around the plant’s base. This insulates the soil, helps retain moisture, and suppresses weeds. Avoid fertilizing bee balm in late fall, as this can stimulate new growth vulnerable to frost damage.
Winter Care for Container Bee Balm
Container-grown bee balm needs extra protection during winter due to increased root exposure to cold. Roots in pots are less insulated than those in the ground, making them more susceptible to freezing and thawing cycles. Move potted bee balm to a sheltered location, such as an unheated garage, shed, or against a warm, protected wall. For added insulation, wrap pots with materials like burlap or bubble wrap, or place them inside a larger container with insulating material packed around them.
During dormancy, container bee balm still needs occasional, light watering to prevent roots from drying out. Keep the soil slightly moist, but avoid overwatering, as soggy conditions can lead to root rot. Good drainage is important, especially in winter, to prevent water from accumulating and freezing around the roots. Smaller pots are more vulnerable to extreme cold and require more diligent insulation and protection.
Post-Winter Emergence and Care
As spring approaches and temperatures warm, bee balm plants will show signs of renewed life. New shoots emerging from the crown signal the end of dormancy. If a heavy layer of mulch was applied for winter protection, gently pull it back as the ground thaws to allow new growth to emerge unimpeded.
Remove any remaining dead foliage from the previous year’s growth during spring cleanup to maintain plant health and tidiness. Once active growth resumes, reinstate regular watering. Apply a light application of balanced fertilizer if the soil lacks nutrients. Bee balm spreads through rhizomes; to maintain plant vigor and control its spread, divide overcrowded clumps every two to four years in early spring. This rejuvenates the plant and ensures continued vibrant blooms.