Don a pair of heavy gloves and a long sleeve shirt. Tuck the shirt sleeves into your gloves so no bare skin is exposed as you harvest nettles.
Grasp the nettle plant by the leaves, about halfway up from its base. With a pair of sharp scissors, cut through the stem just below the part of the plant you are holding.
Place the nettle inside a large brown paper bag. Continue harvesting until the bag is about half full.
Gather the top of the paper bag and wrap twine around it to keep the opening shut. Poke holes in the bag around the sides and in the bottom so air can freely circulate through the bag.
Hang the bag in a warm, dry location by the twine. Dry the nettles for five to 10 days, or until they are completely dry and brittle.
Crush the leaves and stems. Store them in a sealed, airtight container in a cool pantry until you are ready to use them.