Harvest oregano by clipping the stems 2 to 3 inches below the lowest leaves. Gather the oregano into bundles of about four to six sprigs. Tear off any leaves that are dead or blackened because of frost damage.
Wrap a piece of butcher paper loosely around each bundle as if wrapping a small bouquet. Twist the paper around the end of the oregano stems, being careful not to bruise the leaves.
Wrap a twist tie tightly around the stems and paper of each bundle to secure it. Form one end of the twist tie into a hook or tie a piece of string around the bundle in order to hang it up.
Hang the bundles upside down (stems pointing up) in a cool, dry indoor area until the leaves are completely dried out. This may take up to a week depending on your climate and where you hang them.
Break the leaves off the stems and store the leaves in an airtight container. Check the container for condensation after a day or two. If any has formed, wipe out the container and lay the oregano leaves out to dry in the open for another day or two, laying a sheet of butcher paper loosely over them for protection before returning them to the airtight container. Check for condensation after another day or two and repeat as necessary.