Lemon Balm (Melissa officinalis) is a sweet scented member of the mint family. This herb is an easy to grow perennial that does well in zones 4-9. Lemon balm is native to the eastern Mediterranean and western Asia regions. The name Melissa is derived from a greek word meaning bee leaf, due to honey bees fondness to this plant. It is said in ancient Greece sprigs of lemon balm were placed into beehives to attract wandering honeybee swarms and around the outsides of hives to prevent bees from swarming. Medicinal uses of this herb can be found written throughout history for thousands of years. Traditional uses typically involved steeping the herbs in wine for topical application to surgical sites and wounds. 
Modernly the parts of the plant used for medicinal purposes include the fresh or dried leaves of the plants which are rich in volatile oils. The use of this plant mainly focuses on its internal benefits to the digestive and nervous systems. Lemon balm contains powerful antioxidants that contribute to overall health particularly in times of stress and tension. It has been used as a sedative and in treatments for nervous conditions. The herb has also been used effectively against cold sore outbreaks and shingles.
Additionally it can be useful in the treatment of restlessness, anxiety, insomnia, gastric complaints, bronchitis, cold, cough, fatigue, headache and wounds. This is due to the fact that it has sedative, antibacterial, antihistaminic, antiviral, anti inflammatory, antioxidant and antispasmodic properties.
One of the easiest ways to use this herb is through an oral infusion or tea. Simply steep 2-4 grams of lemon balm in 8 oz of hot water to make a delicious sweet smelling herbal tea. It may also be combine with chamomile as an excellent remedy for stomach distress and nervous exhaustion. It’s mild sedative properties are also helpful for stress induced insomnia. Another delicious combination for an evening tea is lavender and lemon balm which would provide a soothing and calming blend to sip before bed.
References:
http://www.ncbi.nlm.nih.gov/pubmed/25680840
http://www.ncbi.nlm.nih.gov/pubmed?cmd=Retrieve&db=PubMed&list_uids=12888775&dopt=Abstract
http://www.ncbi.nlm.nih.gov/pubmed?cmd=Retrieve&db=PubMed&list_uids=15272110&dopt=Abstract
http://www.ncbi.nlm.nih.gov/pubmed/19023806
http://www.ncbi.nlm.nih.gov/pubmed/15636181