Fresh plants that grow in pots, in the garden or in nature usually need light, sun, warmth and water. Only then can they grow, produce leafy greens, active plant substances and strong roots, produce flowers and finally fruits or seeds.
With dried plant parts, this growth and ripening process is complete. Now it's about preserving the ingredients formed during growth for as long as possible or minimizing their loss. Since they can no longer process water, moisture would lead to mold and rot. They can no longer convert light into leaf green through photosynthesis; this would cause the leaf green they still contain to fade. Heat encourages the formation of pests, which like to use herbs as a source of food and as an “incubator” for their offspring.
It follows that if dried herbs are to be stored for a long time, they must be protected from light, air, heat, moisture and pests. Tight-sealing containers are best suited for this, e.g. jars made of brown glass with screw lids. Mason jars are also suitable as long as they are sealed tightly. Basically, these glasses should be stored in a cool, dark room or cupboard. Herbs with a high proportion of essential oils, e.g. sage, rosemary, thyme, ginger, etc., can also be used for a long time (usually several years) without significantly losing their effectiveness.