Basil can be preserved by drying or freezing. To dry the herb, cut stems 6 to 8 inches above ground when plant starts to flower. Hang upside down in warm, dry, dark room, or dry individual leaves on cheesecloth or netting screens. When dry, leaves crumble easily and can be stored whole or crushed in airtight containers. To freeze basil, wash the leaves, pack in ice cube trays and fill with water. When frozen, remove cubes and store in plastic bags. Defrost in a strainer and use as fresh.
