Melissa officinalis L.

Taxonomy and Nomenclature

Melissa officinalis L., commonly known as lemon balm, is a perennial herbaceous plant belonging to the mint family, Lamiaceae.

Growth Habit and Size

It grows bushy and upright, reaching a maximum height of 100 centimetres (39 in).

Leaf Morphology

Its heart-shaped leaves measure 2–8 cm (3⁄4–3+1⁄4 in) long, with a rough, veined surface. Leaves are soft, hairy, and have scalloped edges, and give off a mild lemon scent.

Flower Characteristics

Small white or pale pink flowers bloom during summer.

Lifespan

Individual lemon balm plants can live for ten years; when grown as a crop, plants are replaced after five years to let the ground rejuvenate.

Native and Naturalized Range

Lemon balm is native to south-central Europe, the Mediterranean Basin, Central Asia and Iran, but is now naturalized in the Americas and other regions around the world.

Growing Requirements

It grows easily from seed, and prefers rich, moist soil.

Germination Conditions

For germination, lemon balm seeds require light and a minimum temperature of 20 °C (68 °F).

Propagation

The plant grows in clumps, and spreads both by seed and vegetatively, with new plants growing from fragments of parent plants.

Seasonal Growth Cycle

In mild temperate zones, the plant's stems die back at the start of winter, and regrow in spring. Lemon balm grows very vigorously.

Major Producing Countries

As of 1992, Hungary, Egypt, and Italy are the major producing countries of lemon balm.

Harvesting Practices

In the northern hemisphere, leaves are harvested by hand in June and August, on dry days, to prevent the harvested crop from turning black when damp.

Cultivars

Cultivars of M. officinalis include M. officinalis 'Citronella', M. officinalis 'Lemonella', M. officinalis 'Quedlinburger', M. officinalis 'Lime', M. officinalis 'Mandarina', M. officinalis 'Variegata', M. officinalis 'Aurea', and M. officinalis 'Quedlinburger Niederliegende' — a variety reportedly bred for higher essential oil content.

Commercial and Ornamental Uses

Lemon balm is the main ingredient of Carmelite Water, which is sold in German pharmacies. It is grown and sold as an ornamental plant, and also used to attract bees.

Essential Oil Uses

Its essential oil is used as a perfume ingredient and in toothpaste.

Culinary Uses: Raw and Sweet Preparations

Young leaves can be eaten raw. Lemon balm is used as a flavouring in ice cream and herbal teas, often paired with other herbs like spearmint.

Culinary Uses: Tea and Savoury Preparations

Leaves can be dried for use in tea, and it is a common addition to peppermint tea, mostly for its complementing flavour. It is also added to fruit dishes and candies, can be used in fish dishes, and is the main ingredient of lemon balm pesto.

Flavor Compound Composition

Its distinct flavour comes from a mix of compounds: geraniol (3–40%), neral (3–35%), geranial (4–85%) — the latter two are both isomers of citral — (E)-caryophyllene (0–14%), and citronellal (1–44%).

Additional Culinary Use

It is also one of the ingredients in Spreewald gherkins.