Buds from tree plants are picked in the spring before they blossoms. While the buds are young and closed in their protective leaves they have more aromatic compounds where their curing effeciency comes from.
Leaves should be picked in the begginig of the summer, at dry weather, one or two hours after the Sun rises. It should be picked at its full growing age - at the moment when the propagation organs start to develop (just before blossoms).
The leave should be clean, healthy, whole and to has beautiful green color. You shuoldn't pick the leaves that are dusty, damaged by insects or colorful.
It's picked when at least one half of the blossoms are fully developed. Cut the upper part that shouldn't be longer than 8 - 10 inches. These parts are picked at the same time as leaves - at the moment when blossoms are being developed, but before they develop completely. However aromatic, fragrant upper parts of the blossom branches (rosemary, lavender, Wild Thyme, spearmint) are picked during the blossom developing time.
Of all herb parts, the blossom needs most attention as it can gets. It's the most sensitive part and has the biggest prise and value, even more than leaves or roots. Oftenly, the blossoms are too small to pick them one at a time and sometimes the leaves can be found as fragrant part of the herb, ussualy at the top. In that case, the whole upper part of the herb should be picked.
The plant products can be dry or tasteful. The dry products are picked, before they are completly developed, by cutting the upper parts with the products. Put them on the Sun in order to dry and to develop them completely.