To dry your herbs you need to create the the right environment. Perfect conditions for drying include a consistently high temperature and low humidity. Sun drying is an age old practice but for herbs it can be detrimental, causing colour loss and losing all important volatile oils as well.You’ll want to dry your plant material as quickly as possible before the natural process of decay sets in, but not use excessive heat to speed up the process.
Ovens have been used but the heat tends to be too fierce and there is some anecdotal evidence that microwaves work but, personally, I believe the drying to be uneven. The use of a glass of water to maintain proper microwave conditions also defeats the purpose of keeping humidity low. A dehydrator that circulates the air and has a temperature control works very well.
Ideally you’d have a space that is dry, well aired and where the temperature is consistently between 20 – 32C/ 68 – 90F. Avoid dust and direct sunlight, this will keep your plant material clean and preserve colour.
If your plants are particularly dusty or dirty, or you used chemicals (which I know most of you dont) do wash them. Fill a tub with cold water and dunk your plant material several times to remove any impurities. Lay out on a draining board and pat dry gently between tea towels.
If the leaf is very small you may wish to dry some herbs on the stem, where as larger leaves you may wish to dry individually. Spread your leaves out on trays, frames stretched with netting or hang tied in small bunches. Leave enough for air to circulate freely. Drying time varies depending on thickness, moisture content and humidity in the air. The rule of thumb is to dry leaves until they are crisp and crackly to the touch. This process can take anywhere between 3 days to a week.
If the blooms are quite large, remove the petals to dry. Calendula/Marigold flowers can be dried whole and the petals removed afterwards. Lavender flowers are kept on a long stem and hung tied in bunches to dry.
Like leaves, flowers can be dried on trays or netting but if you need the buds to stay in particularly good shape for decorative purposes then you might wish to dry them upright with stems pushed thru wire trays. Leave until flowers are papery and dry.
Pick seed heads with stems attached and make sure they’re free from insect life. Tie stems into bunches then invert then into a paper bag (do not use plastic, it attracts moisture) and tie the bag around the seed heads. Hang up and leave to dry in a warm, airy place. Once completely dry clean off any pods or husks
Drying roots & bark
Scrub roots and bark thoroughly then chop into small pieces ready for drying. These tougher plant materials require higher drying temperatures and can be dried in the sun. Here the oven can be used quite successfully at a very low temperature and the door left slightly open.
Dried outside on trays or netting it is advised to cover with muslin or the like to keep dust and debris away. The roots/bark is dried when it they snap easily.
Overall drying your own is easy. Just remember to keep it warm, dry, clean and dont let the plants touch while drying.