Contrary to popular belief, when properly stored, most herbs can stay fresh enough to retain their beneficial qualities for years. Here are a few things to keep in mind when storing your herbs:
1. Most herbs (and spices, which are also herbs) will only stay fresh in your refrigerator for a week, or maybe even less, so you need to plan to either use them, or dry them out right away.
2. When drying herbs, one efficient method is to hang them from the ceiling (tied with string at the bottom of their branches) with a bag or tray underneath to collect falling leaves.
3. You can also lay your herbs out on a pan, cookie sheet, or other flat surfaced tray. This can be done as you picked them, or they can be cut or broken apart before spreading them on the surface to dry.
4. If your herbs are fresh, and you wish to keep them that way for some time, most can be sealed in plastic bags and frozen, much the same as you do everyday with their cousins, vegetables. This can also work with dried herbs to preserve them for a longer span of time, but you must be sure no water can reach them, as this can cause mold.
5. If you have dried your herbs, be sure they are completely dry before storing them, or they will mold in their containers.
6. Always store your herbs in dark containers when possible, and then store these in a cool dark area. This will keep them fresher longer, as light effects the potency of many herbs.
7. Above all else, be sure your containers are airtight. Any moisture which seeps in, regardless of other factors in storage, can cause herbs to mold, and the simple exposure to air can cause them to lose potency much faster.
Following these tips to proper preparation and storage is vital when dealing with herbs and spices of all kinds. If done properly, your favorite herbs and spices will be at hand, and in good condition to be both tasty and beneficial anytime you need them for years to come.
Source: Over 20 years of study and experimentation with herbs and other plants.