St. John's wort has been used for thousands of years to promote mental well-being. Traditionally, herbalists knew that the proper time to harvest the unopened buds and flowers was around St. John's Day (June 24), when the plant is flowering. Modern research confirms that most of St. John's wort's valuable constituents are indeed highest when flowering. Planetary Formulas Full Spectrum St. John's Wort Liquid Extract is prepared from carefully harvested St. John's wort that is rich in the broad spectrum of St. John's wort constituents. This is evident from the dark, opaque, burgundy-red coloring of the extract.