Bee balm is usually planted in the spring or fall from container-grown nursery plants. It is a fast-growing perennial that often reaches full height and flowering maturity in its first season. Though not considered invasive, it is part of the mint family and spreads rather aggressively. It will need to be supervised unless you want it to spread. While pollinators love the nectar and songbirds snack on the seed heads, bee balm also makes a tasty tea or garnish, smells lovely in potpourri, and repels mosquitos when the leaves are crushed. Although bee balm plants don’t qualify as invasives (they are native North American plants), they do have tendency to spread aggressively if left to their own devices—both through spreading rhyzomes and self-seeding. The center area of the plant will grow woody and non-productive with time, so you should divide the plants every two to three years in early spring to prevent them from taking over and to rejuvenate the plants. Plant foliage tends to decline after flowering, especially if a common malady, powdery mildew, sets in.
Light
Though bee balm can handle partial shade, it thrives best if it receives at least six hours of full sun daily. Too much shade is known to make the plant leggy and can often reduce the number or vibrancy of its blooms. However, bee balm plants grown in hotter, dry climates will do best if sheltered from the afternoon sun.
Soil
In order for your bee balm to thrive, you should plant it in soil that is rich, moist, and has a pH level of 6.0 to 7.0. Most garden soils are entirely adequate for bee balm. If necessary, poor soil can be amended with compost or manure to enrich it, loosen it up, and make it more amenable to growing bee balm. You can also add a layer of mulch atop your soil to ensure this shallow-rooted plant stays moist.
Water
Bee balm is a moisture-loving plant and enjoys having consistently damp soil. Because of this, depending on your climate and area, you should plan to water the plant at least weekly, never allowing the soil to dry out. It’s especially important to maintain a proper watering cadence in the plant’s first year, as that allows it to establish a solid root system. The standard garden practice of offering 1 inch of water per week will work fine for bee balm. The M. fistula species and its cultivars are considerably more tolerant to dry conditions than M. didyma and its cultivars.
Temperature and Humidity
Bee balm is not particularly picky about its temperature or humidity conditions, so long as it’s planted within its proper USDA zone range (zones 3 to 9). It prefers relatively dry atmospheric conditions, and mildew and rust can become a problem in humid conditions. Provide good air circulation and water at ground level to reduce disease.
Fertilizer
Though not imperative to the plant’s success, you can feed your bee balm plants with a balanced 10-10-10 fertilizer each spring for an added dose of nutrition. Be wary of over-fertilizing, as this can reduce flowering. For the amount to use, follow the product label instructions.
Types of Bee Balm
While some varieties of bee balm sold in garden centers are pure species or direct cultivars, many have complicated hybrid parentage that includes contributions from two or more parent species. The named hybrid types are usually sold simply as Monarda, without any further species designation. The varieties with red or reddish-pink flowers are usually based on M. didyma, while those with lavender or purple flowers have M. fistula as the principal parent. Some of the popular bee balm cultivars include:
Monarda didyma ‘Jacob Cline’ has flowers that are brighter scarlet than the species, notable for drawing hummingbirds.Monarda didyma ‘Pardon My Lavender’ is a short 14- to 18-inch tall with lavender pink flowers. It is notably resistant to powdery mildew.Monarda fistula ‘Claire Grace’ has darker purple flowers than the pure M. fistula species and is known for good resistance to powdery mildew.Monarda ‘Scorpion’ is a 3- to 4-foot hybrid variety with purple flower bracts. It has superior cold hardiness, readily surviving in zone 3.Monarda ‘Marshall’s Delight’ is a 2- to 3-foot hybrid with clear pink flowers. It has good resistance to powdery mildew.Monarda ‘Vintage Wine’ is a 2- to 3-foot hybrid variety with wine-red flowers.Monarda ‘Purple Lace’ is a 1- to 2-foot miniature hybrid with purple red flowers.
Other powdery mildew -resistant monardas to consider are ‘Colrain Red, “Raspberry Wine’, ‘Rose Queen’, ‘Rosy Purple’, and ‘Violet Queen’.
Pruning
Bee balm lovers often embrace the wild, cottage feel of the plant, but it should still be periodically pruned. Deadhead the flowers immediately after blooming to prolong the seasonal flowering and prevent them from self-seeding (unless desired). Deadheading also encourages repeat flowering. If the plants become badly affected by powdery mildew late in the season, to the point of being unsightly, then you can cut the stems back to ground level. This will not affect the health of the plant, and it will return with full vigor next spring. If you want to attract songbirds to your garden, leave the seed heads on the plant through winter. Birds will snack on the seeds. Cut back the stems in late winter/early spring.
Propagating Bee Balm
Bee balm spreads quickly through underground stems (stolons), and the best way to propagate new plants is to dig up the clumps and divide them for replanting. Early spring is the best time to divide bee balm, and doing this every two three years will help keep the plants healthy. Here’s how to do it:
How to Grow Bee Balm From Seed
Bee balm will easily sprout from seeds collected from their dried flower heads in the fall, but most bee balms purchased in nurseries are hybrids, and their seeds often do not “come true” to the parent plant. But pure species plants can be propagated this way, and you can also purchase commercial seeds that have been bred under careful control. Commercial seeds are often sold in mixtures of various colors. Start the seeds indoors about eight weeks before last frost, using small pots or seedling trays filled with commercial potting mix. Sow four or five seeds in each pot, or two seeds in each seedling cell. Place the seeds on the surface and cover with a bare sprinkling of potting mix—the seeds need light to germinate. Place the pots or tray under lights, and water them with a spray bottle. Keep the seeds above 55 degrees Fahrenheit. Do not let the soil dry out. Within a few weeks, root systems will develop. Pot up the plants when they have two sets of true leaves. Make sure to harden off the plants for a week before planting into the garden. Plant when the weather has warmed and all danger of frost has passed.
Potting and Repotting Bee Balm
Although container culture is not common, bee balm is sometimes grown in large containers by urban gardeners who want to attract butterflies or hummingbirds to a courtyard or patio garden. Because a plant needs to be fairly large and expansive to effectively lure pollinators, use a large container, at least 5 to 10 gallons in size. Resin plastic makes a good material, though any well-draining container will suffice. Fill it with a standard potting mix blended with additional compost, then plant the bee balm in the center of the pot. Miniature varieties often work best for container culture. Place the pot in a sunny location and water whenever the top inch of soil gets dry. Potted bee balm plants should be left outdoors for the winter, but should be moved to a sheltered location—a cold frame, or an unheated porch or garage. It is possible to move a potted bee balm indoors for the winter, but don’t expect it to bloom. Bee balm does not make a good permanent houseplant, as it goes dormant each winter. The plant will need to be divided every couple of years to prevent it from becoming root bound in the pot.
Overwintering
After frost kills the plants in the fall or winter, cut back all stems to about 2 inches. Debris should be thrown away rather than added to compost heaps, to prevent fungal spores from persisting. No winter protection is needed in most regions, though gardeners in climates with extremely cold winters may want to mulch the crown to protect the roots from freeze-thaw cycles.
Common Pests & Plant Diseases
Bee balm can be affected by a variety of minor pests, though infestations are almost never serious—possibly because this member of the mint family has a scent that naturally repels insects. By far the biggest problem with bee balm is powdery mildew, a fungal disease that causes a powdery white or gray residue on leaves. While many plants are susceptible to powdery mildew, bee balm is affected much more seriously than most. An environment with humid nights and coolish days is most favorable to this fungus. If your plants succumb to powdery mildew after you have enjoyed the flowers for a while, it may be best to trim them back to the ground and properly dispose of the cut growth. Alternatively, if your bee balm plants come down with powdery mildew too early, and cutting the plants down is out of the question, try spraying with a commercial or homemade fungicide. Repeated applications, beginning early, will be necessary to fully control mildew. To avoid powdery mildew in the first place, keep these perennials spaced at least 2 feet apart from one another so that air circulates well around them. It also helps to water at the base of the plant rather than overhead spraying, which raises the humidity level in the plant’s crown. Bee balm can also be susceptible to rust fungus that can disfigure the leaves. Control rust with spray fungicides if the disease is severe.
How to Get Bee Balm to Bloom
Most bee balm varieties bloom for eight weeks or more at some point in the summer window—usually beginning in midsummer and running into fall. It’s rather rare for there to be problems with these plants blooming, but if the flower display isn’t up to your standards, look to these solutions:
Increase sunlight. Bee balm needs a good six hours or more of direct sunlight each day to bloom adequately, and moving the plant into a sunnier location may help.Lift and divide the plant in the spring. An older bee balm often gets overgrown, with a woody center portion of the crown that doesn’t produce many stems or flowers. Dividing the plant every two or three years will rectify this.Make sure to water adequately. Bee balms thrive in moist soil, and watering weekly will normally ensure good flowering.Inspect for diseases. A bee balm plant with a bad case of powdery mildew will have not only its leaves, but its flower affected.Reduce fertilizer. If your habit is to fertilize all your garden plants on a regular basis, this may cause problems for these light-feeding plants. Bee balms need, at most, a single light feeding in the early spring. More than this may cause robust foliage but reduce flower bud development.
Common Problems With Bee Balm
Bee balms have few serious issues, but it’s common for gardeners to become disappointed with the ratty, sparse appearance of the plants late in the season after the flowering period is over. This is natural for these plants, but it can also be exaggerated if the plant has a bad case of powdery mildew, It’s best to position bee balm plants where their sparse foliage is hidden from view behind other plants—though you need to make sure it has good air circulation. You can also cut off the stems to just above ground level late in the season; this will not harm the plants or stunt their return in the spring.