Source: A Druid’s Herbal, by Ellen Evert Hopman

If you choose to harvest your own herbs please keep the following information in mind.

• Tree leaves should be gathered before Midsummer. After that, the percentage of natural insecticide in the leaf is too high
• Leaves and Flowers should be gathered on a dry day when the flowers first begin to open. They are always dried in the shade.
• Roots are generally gathered in very early spring or in late fall after the plant has begun to die back.
• Tree barks generally contain the desired medicinal properties in the soft inner layer (cambium) between the sapwood and the dead outer bark, or the bark of the root.