Moths can damage wool items even if you store your sweaters and blankets in a cedar chest. The moth larvae do the actual damage, although the only evidence you will see is a holey sweater and winged adult moths. Lavender repels the adults -- using it will keep your wool looking its best.
Lavender oil is a natural way to repel moths and other insects. Place a cotton ball or piece of wool saturated with lavender oil in a closet or storage container to keep moths out. Place lavender oil throughout the home as a deterrent to keep moths away whether you have spotted one indoors or not.
Lavender oil will repel moths and prevent them from forming a home and producing larvae amongst your cashmere and wool sweaters. Lavender oil will not damage your garments, and you do not need to apply it directly to fabric. Lavender oil imparts a more pleasing scent than mothballs, and is a "greener" alternative.
While lavender oil has many beneficial uses, it shouldn't be ingested in large quantities. If you put lavender oil on a cotton ball to repel moths, make sure it is in a place that is not accessible to curious pets or toddlers to avoid the risk of injury.