Monarda Citriodora [mo-NAR-da, sit-ree-oh-DOR-uh] is a flowering plant species from the Lamiaceae family, commonly known as the sage, deadnettle, or mint family.
The Lamiaceae family of plants includes some of the most widely used culinary herbs of the world, such as mint, sage, rosemary, basil, thyme, and oregano.
Monarda citriodora is known for its attractive purple-colored flowers and the distinctive scent its leaves produce when rubbed or crushed.
The smell is reminiscent of lemons, which is why the plant is commonly known as lemon mint.
Even the botanical name of the plant reflects the same; citriodora means lemon-scented.
The first part of the scientific name, Monarda, which is also the name of the genus this plant belongs to, commemorates the 16th-century Spanish botanist and physician Nicolas Bautista Monardes who studied medicinal plants which were brought to Spain from the New World.
In addition to lemon mint, the plant is also known with the following common names:
- Lemon beebalm
- Purple horsemint
- Purple lemon mint
- Lemon horsemint
- Lemon bergamot
- Lemon balm
This wildflower is a native plant to the United States (Texas) and Mexico, the plant grows in a variety of habitats in most of the sunny areas of the region.
In its native range, purple horsemint is seen growing from pastures to sandy and rocky prairies, to roadsides.
Monarda Citriodora Care
Size & Growth
The lemon mint plant grows most actively in the spring, often reaching the height of 3’ feet.
It features multiple stems, which grow from the base and have pairs of lance-shaped leaves.
As mentioned above, the leaves produce lemony smell when rubbed or crushed.
The plant grows and spreads easily, often forming large colonies, however, it has a short life.
Lemon horsemint is an annual plant and dies with the first frost.
Flowering and Fragrance
The plant produces beautiful, but unusual tuft-like, whorled flower heads on elongated spikes.
The flowers are fragrant, tubular, two-lipped, and lavender to pink in color.
Each whorl of flowers is supported by lavender or white leaf-like bracts.
While the bloom time of lemon mint typically lasts from May to July or August (from late spring/early summer to late summer), the plant often continues to produce flowers till the end of summer or even until the beginning of fall, if it receives enough water.
Light & Temperature
The plant prefers full sun, but grows in partial shade as well.
It is hardy to USDA Hardiness zones 5 to 9.
As mentioned above, the plant dies with the first frost.
Watering and Feeding
This Monarda species grows best when its soil is kept continuously moist.
Water it regularly and do not let the soil completely dry out as dry soil makes the plant vulnerable to foliar diseases.
However, make sure to not overwater the plant as well.
The rule of thumb is to water frequently, but moderately.
Feed the lemon plant once every two weeks starting from mid-May to early autumn.
Soil & Transplanting
Although purple lemon mint prefers soils containing a high percentage of clay, it can easily tolerate other soil types too.
However, make sure the soil is well-draining.
Since it grows quite quickly, experts recommend dividing the clumps every three years.
Grooming and Maintenance
M. citriodora doesn’t require a lot of maintenance, but deadheading the flowers is known to help encourage blooming and extending the blooming period.
Experts also recommend treating the plant with copper sulfate or a fungicide once in early spring and then in autumn, as a preventive measure.
How to Propagate Horsemint
Lemon bergamot generally spread by self-seeding.
Provided the right growing conditions, the plant quickly spreads and forms colonies.
But, they also grow from seeds and propagate by plant divisions and stem cuttings.
Growing Lemon Mint Seeds:
- For people living in the warm climatic zones, February is the best time to sow the seeds directly into the ground as they will go through natural stratification during the next two months and will start producing shoots by April.
- When the shoots start to emerge, thin them out.
- The seeds, however, can optionally be sown in autumn.
- If you live in an area where it snows, cover the site with a foil to keep it a little warm.
- When growing this Monarda species from seeds, make sure to not sow them deeper than one inch.
- Seedlings typically start to appear in 3 weeks, but you should wait for another three weeks before transplanting them.
- If propagating through plant divisions, choose the plants about 3 to 4 years old and divide them in April or early autumn.
- Clean the roots of plant divisions with water and then treat the cuts with crushed coal before planting them.
- Cut about 3” – 4” inches long pieces from the green shoots, before the start of the flowering period.
- Remove leaves from lower parts of stems and then plant them in coarse sand.
- Water the plantings, so the soil is moist and then cover with garden fabric.
- Place the pots in a dark place.
- The cuttings typically begin to root within 2 to 3 weeks.
- Transfer the plantings to a permanent place in mid-summer.
Horsemint Pest or Diseases
Lemon horsemint is susceptible to powdery mildew and as mentioned above, it can develop foliar diseases if kept in dry soil for a long time.
The flowers of the lemon mint plant are highly attractive to bees, butterflies, and hummingbirds, which also act as pollinators.
It also attracts beneficial insects to the garden.
Monarda Citriodora Uses
Lemon beebalm is widely grown as a bedding plant in full sun and part shade and is also a popular choice for herb gardens, cottage gardens, prairies, and roadsides.
In some parts of the world, its leaves are used for culinary purposes, such as for making herbal tea.
The flowers are edible, the leaves intensely spicy, and the unusual blooms make easy to use cut flowers.
The plant was also earlier used as a bee repellent, hence the common name lemon beebalm.