To dry lavender leaves, pick large, brightly colored foliage from throughout the plant. Make sure not to pick too many leaves from one section, as this stresses the plant. Spread the leaves onto a tray, and place them in a dark area to dry. Store the dried leaves in an airtight container to preserve their fragrance.
Alternatively, dry the leaves with the rest of the flower by hanging the cut stems upside down in bunches in a cool, dry place. Pick the lavender sprigs when the bottom flowers just begin to open, and cut the stems to approximately 8 inches long. Form the stems into 3/4-inch wide bundles, and wrap the bundles with raffia twine or string, starting at the base of the flower heads and wrapping to the ends of the stems. Keep the flowers out of sunlight, as this fades the colors.
The drying time for lavender varies from three days to several weeks, depending on the weather. Lavender requires more time to dry in humid regions than in arid climates.
Lavender leaves have a multitude of uses. You can steep the leaves and flowers in hot water to make lavender tea, add them to a sachet as a natural moth repellent, or infuse the dried foliage in oil to make a lavender oil.