Do I have moths?

Here’s the unfortunate truth- if you think you might, maybe, kind of have a moth problem, you definitely already do. I learned this the hard way, like so many others with an addiction to thrifting natural fibers will. 

Holes are the telltale sign.

When you pull that mohair sweater from the back of the closet come fall and think, “Huh, I don’t remember that hole being there,” and then wonder if it might have gotten snagged on something, chances are very high that you’ve got a moth problem. In my case, it got so bad that there were actually moths flying around our closets (um… yikes.) But in many cases, you can still have moths without ever seeing any, because it’s the larvae that eat your clothing, and the larvae are very hard to see. So the holes are the way you know. But even if by some lucky chance that sweater did just get snagged, moth prevention is so worth doing either way. An ounce of prevention in this department can be worth many pounds of beloved clothing and textiles. 

If you’re reading this article because you already know you’ve got moths, you might be feeling like I was- desperate and overwhelmed. And if you’re wanting to use exclusively environmentally friendly techniques to combat them, the solution can feel even harder to find. Loads of people and websites recommended moth balls and insecticides, but this was a non-starter for me, just like it may be for you.

So, then what are the earth friendly ways to fight a moth infestation?

The good news is that a lot of the best strategies are actually quite simple and also earth friendly. And many of them just amount to cleaning your clothing and environment regularly. (Easier said then done sometimes I know). I’m going to break the steps down into two categories: (1) moth prevention (2) treatment of an existing problem. Depending on your situation, you can determine which techniques are necessary for you right now, and which things you want to get in the habit of for the future. Remember that in fighting moths, these elements are your friends: heat, sunlight, agitation, low humidity, cleanliness, vinegar.  And these things are your enemy: darkness, lack of use, humidity, dirt and dust.

Moth Prevention Strategies

  • Keep clothes & textiles clean. Moths go for perspiration and food spills. If these aren’t on your clothing, they will have no food and their development will slow. So it’s a good idea to wash any natural fibers regularly. It is also a very good idea to clean anything before storing it. So you will absolutely want to launder your woolens before storing them for the summer, for example.
  • Wear your clothes. Motion and brushing knock the larvae off of clothes. This also works for textiles that experience high traffic. So moths can’t really take hold when items are in use.  That’s why they thrive best when clothes and objects are ignored or tucked away. This is a good argument for letting go of those clothing items that you don’t ever wear. After our infestation at our old apartment, my boyfriend and I got real serious about which clothing items we truly loved and wanted to keep. Let’s just say that as a couple of maximalist collector types, we suddenly had no problem doing a full Marie Kondo on our closets. It’s also the reason that people do old school things like storing their woolens over the summer. Cleaning them & packing them away is great protection during the period when they aren’t being naturally protected by regular use.
  • Agitate your clothes. If you’re not able to wear everything so regularly, or to store things away, it’s not a bad idea to take them outside and just do a good shake or brush off, especially around collars and spots that don’t see a lot of light. Moth larvae are not too clingy and will usually fall off pretty easily with this kind of agitation.
  • Expose clothes & textiles to sunlight. Clothes moths prefer dark spaces. Though the sunlight won’t kill the larvae, it will discourage them from choosing your sunlit clothing as a breeding ground. After washing my natural fibers, I like to dry them on the line outside when possible. I also make a point to open our curtains all the way every morning and let as much light into our house as possible.  
  • Store clothing and textiles securely when not in use. Moths thrive in humid, warm conditions, which is basically summer. So if your wool sweaters and blankets are left forgotten at the back of your closet with old cupcake bits stuck to them, they are not likely to survive the season. A cedar chest or wardrobe is a great option for storing sweaters during the warm months, but plastic bins with gaskets work well too. However, it is very important to launder anything you store before you store it. This is an easy step to want to skip and it’s exactly the step that you really can’t skip. Storing natural fiber clothing with food and perspiration stains or scents on them is like asking for moths to eat them. It’s also a good idea to include some deterents, which I’ve listed below. If you’ve had a recent outbreak, it’s not a bad idea to go through these stored materials once a month and shake them out and expose them to sunlight outside, just to be on the safe side.
  • Make sachets out of moth repellant plants. You can place these around your natural fibers both when they’re in use and when they’re stored. I create moth repellant sachets out of natural materials that I am able to purchase package free in the bulk section or grow in my garden. The most deterent are: Cloves, Cinnamon sticks, Bay leaves, Lemon peels, Lavender, Peppermint, Cedar shavings (typically these do need to be purchased packaged unless you’ve got a carpenter friend) Other possible deterents are: Thyme, Rosemary, Eucalyptus, Dried lemon verbena, Cucumber peel, Lemon balm, Pennyroyal (not if you are pregnant or breast-feeding). Put these in a square of thin cloth like a handkerchief and tie it closed with a piece of ribbon or anything else you have around the house. 
  • Place Conkers/Horse Chestnuts in the drawers, chests and bins where you keep natural fabrics. Supposedly horse chestnuts emit a gas as they dry out and decompose that we can’t sense but which is toxic to moths and other insects. I place them in all of my drawers and in the airtight bins where I keep the textiles I sell online. I haven’t found any hard evidence to support this theory; it’s more of an old wive’s tale. But I am of the belief that old fashioned remedies exist for a reason and probably come out of some kind of age old wisdom. I’ve been using these for a while and haven’t had any problems since my initial moth outbreak, so I’m not planning to stop. I find my supply on Etsy, though I would love to start foraging for them myself at some point.
  • Place cedar hangar discs/blocks in your closet. This is something you’ll want to source sustainably, such as FSC certified. I did find one purveyor in Australia who is selling sustainably sourced cedar blocks. Since then I think some more options have emerged, but it’s a good idea to check whether a seller is actually being transparent about how the wood is sourced, rather than just claiming that it’s eco-friendly because it’s “natural”. I will confess that I’m not currently using these because at the time that I had my moth outbreak the price was just too steep for me. But at some point in the future I would like to add them to my anti-moth arsenal. Also, it’s best to sand any kind of cedar block regularly so they stay fresh and effective.
  • Control humidity. Moths can’t survive in humidity below 20-30% (depending on what source you reference). They thrive in 75%+. So when storing my clothing I like to include a homemade dessicant pack made of bentonite clay wrapped in a little repurposed fabric. You can also re-use the silica gel packets that come with vitamins and other newly purchased items for this purpose. They will eventually get saturated and can be re-dried in the oven and then re-used. I also plan to purchase mini dehumidifiers for my closets, like the Eva-Dry. These are made from plastic, which will be a no-go for some. But they are reusable over and over. I’m hoping to find some used, but wouldn’t be surprised if this is something I end up having to buy new.
  • Vacuum regularly. This is especially important for hard to reach places under chairs and couches. So that exact spot you skip every week because it’s too hard to get to is actually one of the most important to target. These are the exact places moths will hide. (Ugggh, I know.) They typically won’t thrive in high traffic areas. Vacuuming often, such as every week, can be very effective at eliminating eggs and larvae before they ever have a chance to hatch. For this reason though, it’s also a good idea to empty your vacuum cleaner bag regularly, preferably outside. 
  • Clean air ducts & mouldings. Moths can feed on the pet hair and lint that get trapped in these so it’s a good idea to clean them too. I feel like the air ducts are an annual, spring-cleaning thing. I do the moldings whenever I notice them getting dusty. I will typically use vinegar as my cleaning medium here.
  • Clean and/or heat-treat any textiles bought secondhand. Personally I think this is one of the most crucial steps to preventing moths. I think that thrifting used textiles that came from someone’s attic are probably where my own moth infestation came from. Anything that contains a natural animal fiber is potential moth-food. So this isn’t just clothing, but could also be rugs, curtains, upholstered furniture, pillow shams, blankets. How you wash and heat-treat will be dependent on the item itself. Woolens obviously can’t be machine washed on hot. So cleaning in whatever way possible is advisable. For a wool sweater, this might be washing in cold water, drying in sunlight, brushing vigorously and steaming on a very hot setting. Most natural animal fibers won’t be able to go in the dryer, but if it can, it should. Ironing on a very hot temperature is also supposed to be effective at killing all stages of larvae, but this is also a no-no for many natural animal fibers. So for me, washing, brushing, sunlight and steaming have been my go-to methods. Freezing is also a possibility- more on that below. I also inspect things carefully before I buy them. If an item has moth holes, I probably won’t try to save it. The potential collateral damage is just too high.
  • Put vinegar in your wash. This is another one that I couldn’t find any conclusive facts about. When doing a deep dive into moth elimination techniques, I ran across an article that claimed that adding vinegar to the water changes its pH and consequently kills any moth larvae in it. This makes sense to me, so I’ve periodically done this with some of my woolens (I wash them on cold, which I prefer to dry cleaning).

Strategies for an Existing Moth Infestation

  • Breathe. I went into scorched earth mode when I found moths flying around our closet, got completely overwhelmed by all the cleaning I needed to do, and had several bouts of crying. Hopefully you are more level headed than myself, but if this is your case, I’m here to say that it will be ok. Take it one logical step at a time. I’ve detailed the ones I think are most effective below.
  • Isolate the problem items in preparation for treating. If the problem seems to be centralized around a group of sweaters in one drawer for instance, put those sweaters immediately into a garbage bag (I like the If You Care brand) and isolate it somewhere, preferably outside. Then you might pull any natural fibers from surrounding areas and put them into their own garbage bags so that you can assess them later.
  • Clean the affected areas. Moth larvae don’t survive well under agitation. So once you’ve cleared the affected area, whether it be a closet, dresser or chest, you’ll need to clean it. This can be done first by vacuuming, then with soap and water, and lastly with a round of vinegar. Supposedly the vinegar changes the pH of the environment and makes it impossible for moths to survive. I haven’t yet found hard scientific evidence of this, but find it believable. In my closet that was most affected I also went over all the nooks and crannies with a steam cleaner on a very high setting. This may have been overkill, but it gave me peace of mind. I made sure to dry everything thoroughly after the steaming before I placed anything back in it.
  • Vacuum around affected areas. Moths can hide in low traffic areas and corners that harbor a lot of dust. So going over these spots with a vacuum and then emptying it thoroughly outside is wise.
  • Shake/brush clothing and textiles. Moth larva don’t stand up well to agitation. So after you’ve cleaned your closets and carpets, and are ready to open your bags of affected textiles, this is your chance to eliminate many of the larva clinging to them by simply brushing them off. Shake each item out (preferably outside), and run a hand over areas like collars and other spots that don’t see a lot of daylight.
  • Kill any moths that are living in the affected textiles. How you do this may depend on the season. It’s most likely that you have discovered your moth problem in the summer time, because this is when conditions are humid and warm. This will actually work to your advantage because moths can be killed at all stages with intense heat. I have a vehicle, so I was able to do this by hotboxing my bags of textiles in my car. I put all of my affected textiles in a black (If You Care) garbage bag and put that in the car with the windows rolled up on a very hot summer day. To kill them, you need 30 minutes at 120+ degrees or 4 hours at 105 degrees. Because the temperature rises so rapidly in a car, several hours should do it, but I did a whole day for good measure. If you don’t own a vehicle, you can ask a friend for the use of theirs, or just place the bags outside for several hot days. As long as they’re black it will have the same effect- it just may take longer. I have heard of people baking their sweaters and other woolens in the oven, but I didn’t do this because I was too freaked out at the idea of starting a kitchen fire. If you do a google search, you will find detailed instructions on this technique. Of course, do this of your own volition and at your own risk, and please make every effort to be safe. (I think I am obligated to say that I am not advocating for this technique and bear no responsibility for any damage that might ensue.) An alternative to the oven is freezing. This method just takes more time if you have limited freezer space. To do this, you’ll place the affected textile in a sealed tupperware or bag and leave it in the freezer at the absolute coldest possible for at least 72 hours, but preferably one week. It’s important that its container is sealed well, and that you don’t overcrowd the items.
  • Wash the textiles. This is where many advocate for dry cleaning; I obviously wasn’t enthusiastic about that option. Not only is it quite expensive, but it’s also typically environmentally detrimental. I hand or gently machine washed many items on cold. I added vinegar to the water; supposedly this changes the water’s pH and consequently kills any moth larvae in it. This makes sense to me, but I haven’t found conclusive scientific proof of this. I followed the washing up by drying in sunlight. I also steam cleaned a number of articles on a high setting, particularly ones I didn’t feel comfortable washing.
  • Take prevention steps. One you’ve done all of the above you’ll want to take some steps to prevent the moths from developing again. The list above has a number of effective and earth friendly prevention strategies.
  • Repair. If some of your favorite items now have holes in them it doesn’t have to be the end of them. Visible repair can be a lovely technique. See if there is a knitting store in your area or find someone on Etsy like this who can repair the holes in your favorite pieces now that they’re clean and safe.