Showy, aromatic bee balm (Monarda spp.) grows best from divisions or cuttings, but you can also grow it from seed. Bee balm seeds need little to no special treatment to germinate, but the seeds must be planted at the right time and under the right conditions to increase the likelihood of successful germination.
Climate and Hardiness
Bee balm (Monarda didyma) comes from the eastern U.S. and is highly adaptable to a range of climates and growing conditions. It grows best in U.S. Department of Agriculture plant hardiness zones 4 through 9, where it will survive moderately harsh winters once established. Other varieties such as wild bergamot (Monarda fistulosa, USDA zones 3 through 9) and dotted bee balm (Monarda punctata, USDA zones 3 through 8) are slightly more cold tolerant, but they are less desirable for garden use due to their tendency to self-seed.
When to Plant
If you live in a cold climate, start bee balm seeds in the garden in summer or early fall at least two months before the first frost. The resulting plants will bloom the following summer. Alternatively, start the seeds indoors eight to 10 weeks before the last spring frost for planting out in late summer.
In warmer climates, start bee balm outdoors any time, year-round, if soil temperatures alternate between 55 and 70 degrees Fahrenheit between day and night. When in doubt, start the seeds in peat pots in early spring and transplant later.
Bee balm grows best in full sun with moist, moderately fertile soil. Light midday shade will help prevent wilt in hotter climates, but heavy shade reduces blooming.
Till the planting site to a depth of 12 to 15 inches using a tiller or a garden fork. Work in a 2- to 4-inch layer of compost. Break up any large clumps and remove any sticks or rocks from the bed. Water the bed to settle the soil.
Cast the bee balm seeds over the prepared bed, pinch by pinch, until you've made a thin, even layer. Mist the bed with water to settle the seeds into the soil, but do not water with a heavy stream because they will wash away. Do not cover bee balm seeds with soil.
Water the seeds twice daily, morning and night, with a garden hose mist attachment until they germinate. Most bee balm seeds will sprout in roughly one week, but some can take nearly a month. Thin the seedlings to one every 6 to 10 inches after they produce two sets of leaves.
Starting bee balm seeds indoors takes only a few pieces of equipment, plenty of light and occasional watering. This method works inside the home or in a cold frame.
Fill 2-inch peat pots with soilless seed-starting mix, leaving the top 1/4 inch empty. Moisten the mixture well.
Rough up the surface of the seed-starting mix with your fingertips. Spread a small pinch of bee balm seeds over the surface in an even layer. Tamp them gently onto the soil. Light helps germination, so do not cover the seeds with soil.
Place the peat pots on a heating mat in front of an unshaded, south-facing window. Drape a sheet of plastic wrap over the pots to hold moisture around the seeds. Turn off the heating mat at night to create alternating temperatures that mimic conditions outdoors. Alternating between 55 F at night and 70 F during the day is best.
Lift the plastic daily and water if the soil looks nearly dry on the surface. Water with a misting bottle to keep the bee balm seeds from dislodging. Put the plastic back in place after watering.
Watch for sprouting in roughly one week, but don’t be discouraged if it takes more than a month for seedlings to emerge. Remove the plastic covering once the seedlings sprout.
Thin out all but the strongest seedling from each pot. Transplant the remaining seedlings into 3-inch containers filled with potting soil once they produce two sets of mature leaves.
Move the bee balm seedlings outdoors after the last spring frost. Grow them in a sheltered, lightly shaded spot for two weeks to harden off, then transplant them 6 to 10 inches apart in a sunny or lightly shaded bed with fertile, fast-draining soil.
Planting and Aftercare
When transplanting bee balm, dig a hole that is twice the diameter of the plant’s original pot and of the same depth. Position the plant’s rootball in the center of the hole and hold it upright while backfilling with dirt. Gently firm the soil, but don’t tamp it down too much.
Whether started indoors or in the garden, bee balm seedlings need regular attention as they become established. Spread a 2-inch layer of mulch between the plants to keep the soil moist and provide 1 inch of water each week if no rain falls for longer than a few days. Keep the mulch a few inches away from the bee balm's stems.
Bee balm spreads aggressively and can become invasive under ideal conditions, so install a root barrier around each plant or around the entire bed. Make sure the barrier extends at least 12 inches below the soil and 1 to 2 inches above the surface.