Another important thing that you need to know is that you have to use a sharp tool to cut your herbs so you don’t crush or bruise the stems, else they will bleed sap, lose much of their flavor and they may even turn moldy.
This process can also act as a pruning session and will help the plants to keep their bushy and compact shape. If you will do this don’t use any leaves or stems that are brown, wilted, damaged or showing signs of pests and diseases. Use only the freshest, leafiest, upper stems from the plant.
Leaves and shoots may be picked at any time during the growing season but it is better to harvest them before the plant will start to develop flowers. Evergreen herbs may be harvest lightly in winter. Handle aromatic leaves gently because bruising them will make them release the essential oils. Use or preserve herbs as soon as possible after harvesting.
Except from the aromatic leaves of herbs there are some other parts of the plants that can be harvest and used: stems, roots, seeds and flowers.
Stems will be harvest in the same manner as the leaves. Roots may be lifted at any time of the year but their flavor is best in autumn. One of the most used plant for its roots is horseradish. Seeds, from herbs like angelica, fennel and dill can be harvest for later use. Collect the seeds by cutting off whole seedheads in summer or early autumn as they turn brown but before they are completely ripe and starting to shed.
Flowers from herbs have to be harvest on a warm, dry day, when they are fully opened. Flowers can also be used not only for their flavor but as a decoration as well.