Bee balm, also known as monarda, is a flowering plant native to North America. This perennial plant is a favorite of hummingbirds, butterflies, bees, and other pollinators due to its tubular flowers that provide nectar. But does bee balm actually produce nectar that attracts bees and gives the plant its common name?
What is Nectar?
Nectar is a sugar-rich liquid produced by plants in glands called nectaries. It serves as a reward to attract pollinators like insects and birds. The main composition of nectar is sucrose, glucose, and fructose, but it also contains other sugars, amino acids, vitamins, oils, and fragrances. When pollinators visit flowers to feed on the sweet nectar, they inadvertently pick up pollen grains and transfer them to other flowers which enables cross-pollination and fertilization.
Nectar production happens rhythmically throughout the day and life of the flower. Nectar volumes and concentration vary by plant species and environmental factors like temperature, humidity, sunlight exposure, soil nutrients, and water availability. Plants expend significant energy to synthesize and secrete nectar as part of their reproductive strategy.
Floral Biology of Bee Balm
Bee balm flowers are arranged in tiered whorls on a spike. The plants produce multiple flower spikes throughout the growing season from late spring to mid summer. Each bee balm flower has tubular shaped petals in shades of red, pink, purple, or white depending on the cultivar. The petals are fused into two lips, with the upper lip consisting of two lobes and the lower lip having three lobes.
The reproductive parts of the bee balm flower include the pistil and stamens. The ovary at the base of the pistil develops into dry single-seeded nutlets once fertilized and matured. The stamens contain the pollen sacs. The stigma is located under the upper lobe of the flower. When a pollinator enters the flower, its body brushes the stamens and stigma, transferring pollen for fertilization.
Do Bee Balm Flowers Produce Nectar?
Yes, bee balm flowers do produce nectar. The nectaries in bee balm are located at the base of the ovary.
Nectar is secreted from the disc-shaped nectary gland, pooled at the base of the tubular corolla near the ovary. When a pollinator lands on the lower lip of the flower and pushes its head inside, the insects proboscis extends towards this nectar pool to feed.
Multiple studies have measured and analyzed the nectar content of bee balm flowers. The concentration of total sugars in the nectar ranges between 25-40%, consisting mostly of sucrose, along with glucose and fructose. The nectar volumes can reach around 0.2-1.8 µL per flower during peak secretion.
Bee Balm Flowering Period
Bee balm flowers bloom over an extended period in the summer, anywhere from late spring until early fall depending on the region and cultivar. The flowering period can last about 3-4 weeks for each flower spike.
However, not all flowers on a spike bloom simultaneously. Instead, the flowers bloom progressively from the bottom to the top of the spike in an acropetal pattern. This means that there are always some fresh flowers opening and producing nectar while other spent blooms fade away.
The longevity of individual bee balm blossoms is about 3-4 days. During this time the viable flowers continuously secrete nectar during daylight hours, replenishing amounts that are removed by pollinator visits. This extended flowering habit ensures nectar availability over many weeks when bee balm is in bloom.
Peak Foraging Times
Bee balm nectar production follows a diurnal rhythm attuned to the most active foraging times of its pollinators.
Nectar volumes are the highest in the morning hours after sunrise. Secretion decreases in the afternoon and evening but continues at a slow rate through the night. In the early morning, nectar sugar concentration is lowered due to dilution from excess water. The optimal sugar richness coincides with pollinator flight in late morning and early afternoon.
Studies showed that freshly opened bee balm flowers offered the most nectar, while secretion significantly declined in older flowers. The stamens begin shedding pollen two days after the flower opens, when nectar levels are already diminishing. Peak pollen release also coincides with peak nectar availability in the young flowers.
Ideal Conditions for Nectar Production
Nectar production in bee balm is strongly influenced by weather conditions, soil nutrient levels, and access to water and sunlight. Some factors that enable abundant nectar secretion include:
– Warm sunny days between 70-85°F
– High relative humidity between 50-60%
– Rich, moist, well-draining soil
– Regular rainfall or irrigation
– Minimal pest or disease damage
– Little to no fertilizer application
Insufficient water and nutrients, along with environmental stress can significantly diminish nectar quantities in bee balm flowers. However, the plants are resilient perennials that can thrive in a range of conditions with some nectar output.
Main Pollinators of Bee Balm
Bee balm flowers attract an array of pollinating insects and hummingbirds due to their colorful, nectar-rich blossoms. Some of the main pollinators include:
Bees – Native bees forage avidly on bee balm nectar and pollen. Bumblebees, mining bees, mason bees, sweat bees, and leafcutter bees are frequent visitors. The plant’s common name comes from its popularity with honeybees as a major nectar source.
Butterflies – Many butterfly species like the Eastern Tiger Swallowtail, Spicebush Swallowtail, Cabbage White, and Red Admiral rely on bee balm nectar. The flowers provide important nutrition for butterflies.
Hummingbirds – Their high energy needs are met by foraging on bee balm nectar. Attracted hummingbirds include the Ruby-throated Hummingbird, Rufous Hummingbird, and Black-chinned Hummingbird.
Moths – Nocturnal hawk moths like the Hummingbird Clearwing are vital nighttime pollinators of bee balm. The long tubular flowers accommodate their lengthy proboscis.
Other insects – Flies, wasps, hornets, beetles, and beneficial syrphid flies also visit bee balm flowers seeking nectar and pollen.
Ecological Role of Bee Balm Nectar
Nectar production in bee balm flowers serves multiple ecological functions:
Pollinator nourishment – The carbohydrate-rich nectar provides essential nutrients to fuel pollinators like bees, butterflies, and hummingbirds.
Pollination facilitation – Nectar draws in pollinators which transfer pollen between flowers enabling fertilization and seed production.
Interaction with beneficial microbes – Nectar contains amino acids, vitamins and sugars that nourish symbiotic microorganisms in pollinator guts.
Water source – The aqueous nectar provides hydration to pollinators, especially beneficial during hot, dry conditions.
Medicinal value – Antimicrobial compounds in bee balm nectar can protect pollinators from pathogens and parasites.
So bee balm nectar plays a crucial role in pollinator conservation, plant reproduction, ecosystem biodiversity, and mitigating climate change impacts.
Uses of Bee Balm Nectar
In addition to ecological services, bee balm nectar also has some uses for people:
Honey production – Beekeepers often situate hives near bee balm plants since its abundant nectar content produces a light, mildly flavored honey.
Herbal medicine – Traditionally, bee balm nectar was used by Native Americans to treat colds by inhaling the steam from boiled flowers.
Beverages – The nectar can be made into teas, lemonades, cocktails, and even flavored wines. It adds a citrusy taste.
Flavoring – Bee balm nectar has a minty orange aroma that can flavor jellies, candy, desserts, smoothies and more.
However, the primary purpose of bee balm nectar remains the ecological services for plant reproduction and sustaining numerous pollinator populations.
How Bee Balm Nectar Production Can Be Increased
Here are a few tips to maximize nectar secretion in bee balm plants:
– Plant in areas receiving 6-8 hours of direct sunlight daily
– Amend soil with compost annually to improve fertility
– Irrigate plants during dry periods to maintain soil moisture
– Avoid overcrowding and divide clumps every 2-3 years
– Prune spent flower spikes to stimulate new blooms
– Weed regularly to reduce competition for nutrients
– Control pests and diseases that can weaken plants
– Avoid nitrogen fertilizers which cause excess foliage over flowers
– Grow native species suited for local environment
– Provide shelter from wind which can desiccate flowers
– Propagate more bee balm plants to expand nectar resources
With optimum growing conditions, healthy bee balm plants can produce abundant nectar and sustain diverse pollinators.
Conclusion
Bee balm is an outstanding nectar plant that attracts and nourishes numerous pollinators. The flowers produce significant volumes of sugar-rich nectar to fuel bees, butterflies, hummingbirds, and other species. Nectar secretion follows a daily and seasonal rhythm aligned with pollinator foraging activity and the blooming period. Although nectar output depends on growing conditions, bee balm is relatively hardy once established. This iconic American native wildflower has essential ecological value and demonstrates a fascinating coevolution with its pollinators. By understanding the unique floral biology and environmental needs of bee balm, we can better appreciate its connections to the surrounding ecosystem. With species declines worldwide, cultivating bee balm gardens and meadows can create essential habitat and forage to conserve imperiled pollinators.
