Bee balm (Monarda didyma) is a popular perennial garden plant native to eastern North America. It is prized for its brightly colored flowers that attract bees, butterflies, and hummingbirds. Though bee balm has many positive attributes, there are some potential drawbacks to consider before planting this herbaceous perennial in your garden. Understanding both the pros and cons of bee balm will allow you to make an informed decision about including it in your outdoor space.
Susceptibility to Powdery Mildew
One of the biggest downsides of bee balm is its susceptibility to powdery mildew, a fungal disease the appears as a white or gray powdery coating on the leaves, stems, and flowers of plants. Powdery mildew thrives in humid, shady environments. While no variety of bee balm is fully resistant to powdery mildew, some cultivars are less prone to problems than others.
When powdery mildew occurs, the plant’s vigor is reduced. Afflicted plants produce fewer flowers and their leaves can become twisted and distorted before turning brown or yellow and dropping prematurely. Severe infections can greatly diminish the ornamental value and aesthetic appeal of bee balm.
Powdery mildew spores easily spread between plants through wind dispersal. Once established, the fungus can be difficult to control. Good cultural practices like providing adequate sunlight, air circulation, and spacing can help reduce disease problems. Resistant cultivars and fungicides may also be necessary to control infections.
Attracts Unwanted Visitors
Though bee balm attracts desired pollinators like bees and hummingbirds to the garden, its fragrant blossoms may also lure some less welcome insects. For example, Japanese beetles, true bugs, and thrips may visit bee balm flowers to feed on pollen and nectar. While they probably won’t kill the plant, these insects can damage flowers and leave them less attractive.
Bee balm’s minty, aromatic foliage is also highly attractive to rodents like deer and rabbits. These animals may nibble on or completely demolish bee balm plants. Using fencing or animal repellents may be necessary to protect plants.
Some gardeners enjoy bee balm specifically for its ability to draw hummingbirds. However, aggressive or territorial hummingbirds may guard bee balm flowers, chasing away other hummingbirds as well as beneficial pollinators. Providing several bee balm plants can help reduce this behavior.
Spreading Growth Habit
Under ideal growing conditions, bee balm spreads relatively quickly via both seed dispersal and underground rhizome extension. The reddish-purple flowers produce small brown seeds that drop nearby and self-sow readily. Bee balm’s spreading rhizomes allow it to form dense colonies that expand outward.
While the spreading nature of bee balm helps the plant thrive in the wild, it can make containment difficult in small garden settings. Bee balm can outcompete neighboring plants and may require frequent pruning to keep it within bounds. To prevent unwanted spread, some gardeners recommend planting bee balm specimens in pots or maintaining a border strip around plantings.
May Require Staking
Depending on the cultivar, bee balm may grow 2 to 4 feet tall on upright, square stems. These vertical flowering stems tend to be top heavy, especially when in bloom or after irrigation. As a result, bee balm has a tendency to flop over or lodge (bend at the base) without proper support.
Staking or cage supports may be needed to keep bee balm stems upright and maintain a tidy, attractive appearance. Support methods like plant hoops, peony rings, or tall planting companions can help prevent lodging. Staking is especially important for commercial bee balm crops grown for cut flowers.
Deer and Rabbit Damage
As mentioned previously, deer and rabbits are extremely attracted to the minty scent and flavor of Monarda leaves. These animals will readily browse on bee balm, sometimes eating the plant entirely to the ground. Severe defoliation can leave the plant stressed and unable to flower properly.
Physical barriers like fencing are the most effective way to protect bee balm from deer and rabbits. Repellent sprays made with rotten eggs, hot peppers, or other natural ingredients may offer some protection. Predator urine sprayed around plants can also help deter grazing. Planting bee balm in an inaccessible area is another option.
Aggressive Growth
Bee balm spreads readily by seed and underground rhizomes, forming expanding clumps that can reach 3 feet or more across. This aggressive growth makes bee balm well suited for naturalizing in meadows and open woodland areas. However, its determined spreading can make bee balm difficult to control in small garden settings.
Regular division of mature clumps every 2-3 years helps restrain bee balm. Removing spent flower heads before seeds develop also curtails self-sowing. Site selection is key – allow ample room for growth or plan to dig out and discard portions regularly. Using rhizome barrier around plantings is another option.
Potential to Spread Invasively
While native to eastern parts of North America, bee balm has the potential to spread invasively outside its native range. For example, some populations have established in natural areas of Oregon and Washington, where bee balm did not originally occur. Its seeds spread readily by wind, water, animals, and humans.
Gardeners should be aware of the invasive potential of bee balm, especially types that freely self-sow. Avoid planting bee balm in areas where it could impact native species. Deadhead spent flowers and discard seeds rather than composting to prevent unwanted spread. Know the legal status of bee balm in your region.
Toxicity to Horses
Horses should not graze on or consume any part of bee balm plants. The essential oils in Monarda contain the compound thymol, which can cause toxicity and nerve damage in horses if eaten. Small amounts may cause mouth irritation, drooling, and head shaking. Larger doses can lead to staggering, tremors, increased heart and respiratory rates, and collapse.
Bee balm occasionally escapes from gardens into horse pastures. Check fields regularly and remove any bee balm that appears. Fence garden plantings to prevent access. The fresh or dried leaves and flowers can be toxic whether green or dried in hay, so exclude bee balm from horse feeding areas entirely.
May Require Staking
Depending on the cultivar, bee balm may grow 2 to 4 feet tall on upright, square stems. These vertical flowering stems tend to be top heavy, especially when in bloom or after irrigation. As a result, bee balm has a tendency to flop over or lodge (bend at the base) without proper support.
Staking or cage supports may be needed to keep bee balm stems upright and maintain a tidy, attractive appearance. Support methods like plant hoops, peony rings, or tall planting companions can help prevent lodging. Staking is especially important for commercial bee balm crops grown for cut flowers.
Deer and Rabbit Damage
As mentioned previously, deer and rabbits are extremely attracted to the minty scent and flavor of Monarda leaves. These animals will readily browse on bee balm, sometimes eating the plant entirely to the ground. Severe defoliation can leave the plant stressed and unable to flower properly.
Physical barriers like fencing are the most effective way to protect bee balm from deer and rabbits. Repellent sprays made with rotten eggs, hot peppers, or other natural ingredients may offer some protection. Predator urine sprayed around plants can also help deter grazing. Planting bee balm in an inaccessible area is another option.
Conclusion
Bee balm is a showy, fragrant perennial that makes a bold statement in garden beds, borders, and pollinator plantings. However, like any plant, it has some potential drawbacks to consider before adding it to your landscape. Key cons to weigh include powdery mildew susceptibility, spreading growth habit, deer and rabbit damage, and its tendency to attract unwanted visitors. With proper site selection and care, these issues can be successfully managed. Understanding both the advantages and disadvantages of bee balm allows gardeners to make informed choices about including this popular plant in the garden.
