Herbal Moth Repellents

Any of us that work with natural fibers, especially protein fibers are in danger of having our precious material damaged or destroyed by pests. Moths, silverfish, fleas (they are a nuisance), mold, beetles (not to mention the kids, cats and dogs) can eat undetectable holes in silk and animal wools.

Cellulose fibers are generally left alone except when left damp.   Then mold and mildew can be a problem. But we are not going to discuss that further than to say be sure to store the cotton, linen, flax and basket weaving fibers, finished or unfinished in a dry closet or drawer and checked occasionally for mildew.

Mable Grey has a very strong lemon drop scent.  I have never had a pest problem where I put this pelargonium.   004.gif (865 bytes)

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What I will discuss is storage, treatments and repellents for our protein fibers, in the raw, washed and unspun, spun and finished.


First we need to discuss the pests that eat up our fiber. The most common and damaging are the moths. Two types of moths (UCDavis moth site) are found in our area (Southern California) that eat protein fiber these are not the same moths that we find in our kitchen but look very much the same. The moths go through an egg stage, a larva stage, a pupae stage and an adult moth stage. The moth is only damaging as a larva when it does all of its eating. The moths can be detected and destroyed at any stage. The female adult moth never wanders far from where she was laid as an egg and the males fly around to find the females so most infestations are rather confined. But it only takes one larva to bore through a cone of yarn and ruin the whole cone cutting the 2000 yards into 4 yard pieces or weakening a skein of yarn so as to break when tension is placed on it. The eggs are clear white and round, very much like a flea egg. The shell left when the eggs hatch are a little yellow and brittle the larva are very small and grow at a speed proportional to the temperature and available protein and fat (grease in the fiber). The larva usually do not grow any larger than 5/8 inch long and are much thinner than the larva we find in the food moths. One variety spins a silk casing resembling the fiber that they eat and are very difficult to detect at this stage except by the damage they create. Both these varieties are very hardy.

wpe89.jpg (10795 bytes) Lady Plymouth, a rose scented pelargonium.

Equally damaging to our protein fibers is the little wool or carpet beetle (UCDavis carpet beetle site). Fully grown it is about 1/4 the size of a small lady bug. It is gray and white or black and gray dotted. It also goes through the various stages that the moth does with its larva being the most damaging stage. Its larva looks like a small squat fuzzy cross between a caterpillar and a sow bug. Now these little buggers travel a bit faster than the moth larva, they can make it across the room in a couple of days. I find that they have a enormous appetite especially for raw fibers with light oils on them. The adult can fly.

Silverfish can and will eat not only your protein fibers but also the cellulose fibers but they seem to like the labels more than the fibers and are not on my list of worst enemies. Anything that we use to protect against moths and beetles will kill silverfish.

Fleas are only a nuisance from the standpoint they will lay eggs and leave residue in your raw fibers especially dog hair, angora and similar fur fibers.

Care and feeding of Pests

The larva of the moths and beetles need more than just protein to survive and grow. The time span of their life cycle varies with the temperature and abundance of food.  It can be completed in less than three weeks if the climate is warm and moist, and food is plentiful. Or, it can take up to four years in colder weather with little to eat. They can tolerate a frost and being frozen in the egg stage for some period of time depending on what temperature they are frozen at. Three weeks in a deep freeze below 10 degrees F will kill the eggs (number one way to kill bugs without damaging fibers or using chemicals). Heat will also kill the pests at all stages of life. How much heat? A dry attic is usually too hot in the summertime as is the top of the garage; but, a warm closet or the floor of the garage is perfect breeding ground. You can zap the pests in the Microwave but it takes actually heating up the fiber by the time you've killed the moths and eggs. This is not a safe, efficient or effective means of killing insects. They are surprisingly tolerant. (I once watched them fly around in the mircowave for 5 minutes without dying.)

As the moths and beetle larvae eat your wool or yarn or garment they need oil or fat, and minerals to digest the protein. Raw fiber, fleece in the grease, angora, dog hair, llama, mohair that spinners like to spin fresh off the animals are the prime target for protein eating pests. At one point I had skeins of handspun yarn in a perfect environment for moths: one skein of angora (handplucked and unwashed), Samoyed (washed), camel (spun from processed roving), silk (spun from brick), wool (spun in the grease then washed), mohair (washed then spun), mohair (washed spun and dyed), angora (dyed and spun), wool (washed dyed and spun). At the end of three months the natural angora was dust, the Samoyed was in yard long pieces, the un-dyed wool was in yard long pieces the un-dyed mohair had too much damage to use, the commercially processed fiber was damaged but still usable as weft in scarves, the silk was untouched. This disaster prompted me to think of preventative measures to protect the fiber. Since this time I have seen fleeces, in the grease left in sheep growers barns for a season devastated by moths. The larva needs grease to do their damage. If at all possible, store your fibers clean. Put your finished handspun yarn away scoured (leave no oils in them if possible). Make sure your sweaters, scarves, hats, blankets and rugs are stored clean. Your body oils, sweat and even the oil off your hands, or a spot from last nights dinner is fuel for these fiery little pests.

OK, so we know we should keep our protein fibers oil free. But what about that water resistant sweater that we bought in Scotland last summer, they say not to wash it but to air it. What about all that beautiful Australian fleece, in the grease that is so lovely to spin. "Are you telling me that I should be washing the 15 pounds of plucked angora I have stored in the attic along with the twelve pounds of samoyed that the eccentric lady has me spinning?"  This stuff could easily become a felted mass or even worse slip down the drain disappearing forever when we rinse it (not really forever, hubby will find it when he's under the house trying to open the sewer pipes). And that handknotted rug on the floor, a bit soiled but impossible to wash and would the bugs really be after it? YES!!

Go ahead and air the sweater. If it begins to get a little ripe with age and wear, rinse in warm water roll the moisture out of it with towels. Dry it flat out of the sun; this will remove all but the lanolin. Store the sweater with moth ball (yuk) or an effective herbal repellent that I will be discussing. Store the greasy fleeces in pillow cases or cardboard boxes lined with newsprint. Let the fleece breath; do not pack too tight; do not expose it to heat. DO add insect repellent. You will only want to store your fleece in this manner up to a year. About this time the lanolin begins to harden and get waxy and is difficult to wash out. If you plan to wait that long to spin it, you might as well wash it and store it clean. It is safer and less time consuming in the long run.

wpe93.jpg (7624 bytes) Peppermint Geranium has a refreshing, soft mint aroma.  It is not the best pest repellent. Angora, llama, dog hair or any of the short soft flyaway fibers that are difficult to wash until they are spun are best stored with repellent in cardboard boxes lined with newspaper. If the fiber is stored in plastic bags they have a tendency to matte down and felt. The plastic is not much protection from bugs as they can and will eat right through. It is best to close the flap on the top of the boxes to trap the odor of the repellents in the box.

Your hand hooked rug can be spot treated to removes small soils. If it has a heavy nap it is sure a breeding ground for all types of pest including fleas. If you think that because it is out in the open and is getting traffic that it is not susceptible to pest you are wrong. Dust the rug with commercial dry carpet cleaner or with santolina or pyrethrum found in the painted daisy. We know that it is possible to store fibers dirty but that clean is better.

Clean fibers should still be stored with insect repellent as the fiber still can still be eaten, just slower. Moth ball and herbal insect repellent need to be in a closed area for sometime to be effective. If a closet is opened daily the fumes escape and the larva can survive. A cedar chest that is kept closed and still has its original oils will suffocate larvae. If the oils have been dried out with time the chest need to be sanded to release fresh wood and new oils, or re-oiled by a commercial oil available but expensive. A natural herb repellent can be placed in the chest and will work fine. If our yarn or garment is washable and stored in a closet or drawer that is not always closed, I suggest using a herbal rinse on the fober that will leave it clean and fresh smelling. The rinse is repulsive to bugs until the next wash. The rinse can also be used on kittens and puppies to prevent fleas until they are old enough for commercial dips. Anything packed too tight (such as a cone) will not allow the fumes to reach portions of the fiber. Special care must be taken to ensure that no pests are present around these fibers.

We have now discussed what you need to do with a few individual problem fibers and the state they are in. But how and why do they work? Mothballs are a poison to us and the bugs. They come in a crystal form than dissolve when exposed to air. As a fume, they permeate the area poisoning the larvae. adult moth or beetle when the fumes reach a high enough toxicity level. It must be quite high and opening the drawer, box or closet everyday will not allow the fumes to reach this level even though the closet will smell heavily of mothballs. Even at toxic levels the fumes will not penetrate a tightly wound ball of yarn or a large stack of skeins. Neither will a sachet of herbal repellents. The difference is that the herbal repellents will not hurt us.

Herbal insecticides work in one of two ways: as a repellent, repugnant to the pests or as a poison to the pest. Making our potpourri or rinse with a combination of both is the best way to insure success at storing our fiber.

What plants make good repellents and how do we prepare the potpourris and vinegars. I like to separate the plants by aroma (masculine and feminine) and effectiveness. I do not worry as much if it is a repellent or a poison. In the quantities we are dealing with here none are toxic to us though you may have an individual allergy to one plant or another. All of these plants can either be grown in your flower beds below your larger bushes or collected from a neighbors trees. Most can be grown from seed, started from clippings or found at a local nursery. Many of them can be used for cooking and some make wonderful tea. For potpourris cut the herbs in the morning before the heat of the day and dry in the dehydrator or hang upside down in a dry dark place like the garage. Wet potpourris are more fragrant but not suitable as insect repellents. When the herbs are dry mix as desired and store in airtight container or ziploc bags. Most sources will suggest that you use only the flowers or leaves of the plant. But many of the plants have much oil in their stems as well, I suggest using the stems of these plants and them putting them through the food processor to mince them and fill sachets. Herbs for vinegar should be picked and used fresh. Some of the herbs can be picked fresh and placed directly in the rinse water of the fiber, yarn or garment left there to soak and permeate the fiber. A delicate but effective essence will be left on the wool.


Bay (laurus nobilis), a bush or tree; leaves used to season foods also to repel bugs in your flour. I have not found it strong enough to deter pest larvae in wool.

California Bay Laura (umbellularia californica), not edible is slightly strong and can deter moths in flour, it is suitable to be added to a masculine potpourri.

Bergamot, easy to grow, excellent repellent. Use in all forms of insect repellents, great for tea.

Coriander (annual grown easily from seed) has a strong pungent odor, the seeds are suitable for any potpourri, vinegar or rinse, leaves and seeds are edible, save some seeds for next years crop.

Citrus (oranges, lemon, grapefruit etc.) use the flowers for potpourris or rinses, use the rinds of the fruit dry for potpourris, excellent.

Hyssop is both a moth and flea repellent use dry in potpourris.

Lavender, any variety but old English is the hardiest. Very good luck from seed or purchase small plant at nursery. Very showy flowers all the sunny months, continue to cut back the plant to promote more blooms, may harvests all summer. Evergreen through the winter. Takes full sun all day but will tolerate half a day of sun. Tolerant to dry soil. Excellent for any potpourri, vinegar or rinse. Leaves and stems are as fragrant as flowers. Suitable for tea.

Lemon Balm a member of the mint family, edible, good for tea and cooking seasoning, good for all potpourris somewhat mild for vinegar or rinse.

Mints (Orange bergamot, pennyroyal, peppermint, spearmint, apple and pineapple) effective in that order, all excellent for tea, potpourris, vinegars and rinses. Orange bergamot, not a true bergamot has a pungent odor when fresh but mellows and is sweater and strong when dry; is very easy to grow. Do not use pennyroyal for human consumption.

Pyrethrum, harmless to people and pets but deadly on contact with pest. Use by itself dried and ground, in potpourris, vinegars or rinses.

Rosemary, grow a well trimmed plant for yourself or trim the neighbors hedge once in a while, excellent for seasoning food, potpourris, vinegars and rinses. Goes well with masculine mixes of herbs.

Rue, if you can stand it in your garden is edible, a good seasoning but only a mediocre repellent, add to masculine mixes.

Sage, Now in so many exciting varieties making colorful borders in the garden, a good natural dye, edible and an excellent repellent for all types of potpourris and vinegars, a little week as a rinse.

Santolina, both gray and green are very hardy, showy in bloom and can be trimmed into a nice cushion or border. The best insecticide I've used dry, good for vinegar, use very hot water to release its essence for a rinse then add to rinse water. This plant is sometimes called Cotton Lavender but is not related to lavender.

Scented Geraniums Pelargoniums (second best to Santolina) Effectiveness varies by species, This very strong lemon of an African variety is best, lime that is very common locally is good, as is peppermint, chocolatemint, oakleaf, rose and perfume scented. Cut and place in vase with water or without to freshen a room. Use in cooking, potpourris, vinegars and rinses, Excellent in tea.

Southernwood (Artemisia Abrotanum) excellent pesticide use like santolina. but sweeter.

Tansy takes up a little more room but is excellent as a repellent in all ways, the dried flowers are showy.

Thyme is not only a wonderful seasoning but very good for vinegars.

Sweet Woodruff, a shade loving herb is stronger in aroma as it dries and very good for potpourris of all types.

Of the trees, Eucalyptus leaves are best from any variety, they also can be used for dying, is good as an additive when available and of curse cedar shavings, Dried juniper can be added to woodsy smelling potpourri.

The herbs and plant I have mentioned are all very good for these uses but there are many others that I have not personally experimented with or have little knowledge of.

To use the potpourris you have made, place the mixture in open mesh bags, hand-woven fabric or cheesecloth, crocheted or knitted bags are good too. Place with each sweater or in the center of a pile of yarn, with each box, bag of raw fiber. Make sure it is in a closed area so the fragrance can strengthen and permeate. Keep the lid on boxes and the drawers shut, use plenty. Discard by mulching into the yard every two years and start with fresh. Check your storage every season. Clean and remove any infestations.

To make vinegars, follow the recipes I have available. Get inventive. To use vinegars: pour a cupful in the last rinse of each wash let set a few minutes, drain and dry. Many of the vinegars are suitable for cooking.

To use fresh herbs as a rinse: If you are rinsing in very hot water just place the herb leaves, flowers or stems directly in the water with you fiber, you may wish to place the herbs in a net bag and swish in around. Let seep for a few minutes, smell the aroma, drain the dry. Be sure to let the herb sit on the fiber causing possible discoloration. If you are using a warm or cold rinse, boil water and make a tea out of the herb then add the tea to the rinse water.

Last updated 6/2/2011