You can dry herbs throughout the growing season as time allows. For best results, harvest them on a sunny day during a dry spell, and wait until the morning dew has evaporated before harvesting.
If evening is the best time for you, harvest before the dew forms again. Harvest the herbs with scissors and shake off any surface dirt. Then cover the cuttings with a towel as you work to protect them from shriveling in the burning sun.
Don’t bother to wash the herbs unless they are very muddy. Just begin drying them as soon as possible using one of the following techniques:
To hang-dry herbs, first lay stalks on a counter and sort by size. Bunch four or five stem ends together and fasten tightly with wet twine, rubber bands, or twist-ties. Hang the herbs out of direct sunlight in a dry area with good air circulation. You can string a clothesline in an unused room of your home and use clothespins to secure bunches of herbs to the line. If there is no available space out of direct sunlight, put the herbs in paper bags with the stem ends coming out of the top of the bag. Cut several holes in the bags to allow for air circulation, and hang them.
For screen drying, set up screens on wood blocks to provide air space. Set them out of direct sunlight. The herbs can be just touching each other, as they’ll shrink. Lay herbs in a single layer on each screen. If you don’t have a good supply of screen, you can spread out the herbs in a single layer in wicker baskets for drying.
Probably the easiest way to dry herbs is with a food dehydrator. Just follow the instructions that come with the dehydrator.
You can also dry herbs in a microwave oven. Spread a cup of herbs in a single layer between paper towels. Turn microwave on high for 30 seconds. Turn the herbs over and microwave on high for another 30 seconds. Repeat this process until the herbs feel brittle and rattle when you shake the paper towels. Total drying time is about 3 minutes. Take care not to overcook or the herbs will taste scorched.