- You will get 350 Seeds of Lemon Balm Culinary Heirloom Herb Seeds. - Sunlight: Full Sun, Medium Sun. - Life Cycle: Annual. - Watering: Medium. - Lemon Balm Seeds - Botanical name. Melissa officinalis Origin. Europe and Asia. - Lemon balm is a perennial herb, a member of the mint family. It grows 12 to 24 inches high and about as wide. Lemon balm is shallow-rooted and fast-spreading. It has lemon-scented, oval, toothed leaves, opposite arranged on four-sided stems. Lemon balm flowers in summer; the small white flowers are borne in tight clusters at the leaf axles. Lemon balm is deciduous; it will die back to the ground in freezing weather, but regrow from the roots in spring. - Yield. Grow one lemon balm plant per household. - Site. Plant lemon balm in full; it will tolerate shade. Grow lemon balm in well-drained, sandy loam; lemon balm will grow in almost any soil. It prefers a soil pH of 6.7 to 7.3. - Planting time. Lemon balm is a hardy perennial herb that grows best in cool weather. Sow lemon balm in spring about the average date of the last frost. Seeds can be slow to germinate. Also sow seed in late summer. Root divisions can be planted at any time during the growing season but will become established quicker in cool weather. Cuttings from new growth can be started in moist sand. - Planting and spacing. Sow lemon balm seed OE inch deep. Thin successful seedlings to 8 inches apart and later to 18 inches apart. Space rows 18 to 24 inches apart. Lemon balm spreads by underground roots. To keep lemon balm from spreading, set it in the garden in a container that will keep the roots in place. Remove unwanted plants before they become established.