If picking herbs could be possible during the whole year, then it wouldn't be necessary to dry it and to keep it. Since, it's not the case you need to dry the plant after you pick it and to keep the plant in that condition until you use it. Fresh plants are subject to fermentation and they can become faulty because there is a lot of water in them. Therefore, in order to avoid bad changes, that cause herbs to lose their curing effect, we must dry them just after we picked them. This is how they lose water which is one of the main factor that cause unwanted changes in them.
Drying is the easiest way to conserve the herbs. Yet, that job is delicate and requires a lot of attention and work to reach the goal - to completely preserve its curing ability for a long time (to get the herb that is not the subject to inner or outer changes). In other words, we need to reduce the water in the herb and to keep all the ingredients from changing. And the best proove that we did the job properly is preserved natural color and lovely smell which a fresh herb has.
Before drying, the picked herb or its parts (leave, blossom, root, product...) must be checked to see if there is something wrong with it (damaged leave for example) or are there insects or dust. If there are then remove them. In the drying process we must follow one basic rule: thender parts (blossoms, leaves, buds...) must be dried serarately on a clean thick paper or wooden table and putted on a fresh air protected from the Sun lights.
Fragrant plants that has oil in them must be dried in a closed space. The leaves or the whole plants which dry too long and slowly, sometimes lose their fragrance and get black color. In that condition they cannot be cures and oftenly is dangerous to use them.
Direct Sun light and heat are used to dry fleshy herb parts (roots, cortex, products) that must be cutted out into small pieces and putted on the roof or wooden tables.
The blossoms must be dried out as soon as possible. Blossoms should never be putted into the Sun light, because the sun light destroys the structure of their ingredients. Sometimes, it is allowed to dry these with the Sun light, but it has to be done quickly, and the material you dry must be putted into thinly layers so you don't have to rool it and harm the material.