Lavender can be very effective on repelling moths. First you need to clean the area where moths have been to get rid of them. Lavender will not kill or remove moths.
It is not the adult moths that damage clothes, but the larvae (tiny, white worms) that is from the moth's eggs. In fact the adults do not eat nor live long. An adult female can lay between 100 and 150 eggs. The eggs hatch in about five days and it is all down hill from there for clothes or yarn. The larvae commence eating the fabric/fibers. The larvae will continue eating until they enter the cocoon stage.
Lavender and cedar (and eve, moth balls) do not actually kill the moths, their eggs, or the larvae. They mask the male's ability to smell female pheromones, therefore the males can not locate the females to mate and thus the female do not lay eggs.
Before using lavender and/or cedar you need to get rid of any eggs, larvae, or cocoons in your yarn, fabric, or other fibers.
Wipe down all storage bins or drawers where the items are located with a wet cloth or sponge. Locate the eggs and/or larvae and get rid of them. Try shaking the items out. If it is the summer, try putting them outside in direct sun light, which may either kill or drive away the eggs and larvae.
We suggest using one lavender or cedar sachet every 5 feet or so to insure that the fragrance of lavender/cedar is strong enough to smell.
If the fragrance fades just give the sachet a squeeze to release the natural oil inside of the lavender buds. Replace the sachet whenever you no longer smell the fragrance of lavender even after giving it a squeeze. Lavender has a shelf live of approximately two years.