The tradition of harvesting herbs on the summer solstice stretches back through prehistoric ritual and European pagan culture, rooted in the belief that when the sun was at its most powerful, herbs would be at their most potent too. And there's some science behind that idea.
Many herbs reach their peak concentration of essential oils (the compounds responsible for flavor and fragrance) in late June, just before they flower. The solstice also falls before peak summer heat and drought begins to stress plants and divert their energy into seed production. 'Harvesting them before they start to decline makes sense,' says C.L. Fornari, National Garden Bureau member and host of The Garden Lady radio program. 'Additionally, many of the herbs have not yet started to divert their resources into making seeds.'
