Why Does My Merino Wool Get Holes? [Definitive Guide!]

There’s nothing more frustrating than spending good money on high-quality merino wool clothing, only to have it develop holes and wear out faster than expected. As a breathable, moisture-wicking, and antimicrobial fabric, merino wool is prized for its comfort and versatility.

But its delicate fibers can be prone to damage if not properly cared for. The sad truth is that even with the best care, merino wool is still susceptible to pilling, snagging, and eventual hole formation over time.

Not to worry! With some diligence and preventative measures, you can prolong the life of your beloved merino pieces.

In this guide, we’ll explore the common causes of hole development in merino wool, as well as tips and tricks to keep your knits looking great for seasons to come.

Why Does My Merino Wool Get Holes?

Merino wool can develop holes due to moth larvae eating fibers, abrasion from zippers and hooks when washing, using regular detergent instead of wool wash, and friction from rubbing against other fabrics. To prevent holes, store wool sealed in plastic bags, wash by hand in cool water with wool detergent, lay flat to dry, and mend any holes promptly. Proper storage and laundering are key to keeping merino wool hole-free.

Factors Contributing to Holes in Merino Wool

Let’s discuss factors that contribute to holes in Merino wool:

Delicate Nature of Lightweight Merino Fabrics

Lightweight merino wool is a term that refers to the weight or thickness of the fabric, not the quality or warmth. The weight of merino wool is measured in grams per square meter (GSM), which indicates how much fabric is in one square meter. The higher the GSM, the heavier and thicker the fabric is.

Lightweight merino wool typically ranges from 120 to 180 GSM, which means it is thin and light. 

For comparison, midweight merino wool ranges from 190 to 220 GSM, and heavyweight merino wool ranges from 230 to 320 GSM. 

Lightweight merino wool is ideal for warm to hot conditions, as it provides a light layer that can keep you cool and comfortable. It is also suitable for layering under other garments in colder weather.

When woven into fabric, lightweight merino has a looser, open weave to enhance softness and breathability. But this also means less yarn density and structure. So there are ample holes and gaps for snagging to occur.

Merino fibers, while crazy soft, don’t have as much tensile strength as thicker sheep’s wool. So when pulled lengthwise, they can snap more easily. And with a lightweight, open weave, there’s less crisscrossing of yarns to share and reduce stress loads.

Additionally, lightweight merino yarns have less twist. This adds to their cloud-like drape and comfort against the skin. But it also makes them less resilient compared to tightly twisted yarns.

Over time, the soft merino fibers can break free from the loosely woven fabric. This causes little fuzzy balls called pills. If the pills get rubbed a lot, they can turn into holes. Even a small snag can make a hole start to form.

Washing merino wool also causes problems. Merino fibers have lots of tiny scales that overlap. When the fibers get wet, the scales lift up away from the fiber. This makes the fibers rub against each other more. The friction causes the fibers to break.

Hot water and heat from drying make the fibers even weaker. With the loose weave and low twisting, holes can start to form when the garment is washed.

1. Pests like moths, carpet beetles, and silverfish


Moths are likely the first pest people think of when it comes to damage on wool clothing and textiles.

The larval form of clothes moths, known as woolly bears, like to munch on keratin, the protein fiber that makes up wool. There are a couple different species of moths that tend to infest wool.

The most ubiquitous is the webbing clothes moth (Tineola bisselliella), identified by the silky tunnels and patches it leaves behind on fabric.

The larvae graze on wool by scraping off the surface, leaving small bald patches that may eventually turn into holes.

They spin silken burrows to live and feed inside, which can also compromise the integrity of the wool.

Casemaking clothes moths (Tinea pellionella) get their name from the portable cases the larvae construct out of fibers from their food source.

They eat wool and other animal fibers in a similar fashion to webbing clothes moths. Both types of moths prefer to live in dark and undisturbed places, such as closets, drawers, or storage boxes.


Silverfish are equipped with chewing mouthparts suited for breaking down cellulose and carbohydrates – substances found in book bindings, wallpaper, photos, and textiles.

Silverfish are also nocturnal and like to live in moist and humid places, such as bathrooms, kitchens, basements, or attics.

When indoors, silverfish can gnaw irregular holes in merino wool garments (especially if they are stained with food and sweat) and other animal fiber products while they search for edible paper or starch residues that may be present.

Like moths and carpet beetles, silverfish need moisture and prefer warmer environments. So, clothing and textiles stored in attics, garages, or basements make easy targets.

Carpet Beetles

Carpet beetles are a common household pest that can damage wool fabrics and clothing. The larvae of the varied carpet beetle (Anthrenus verbasci) are particularly attracted to wool items and can eat holes in them.

These tiny larvae are equipped with specialized mouthparts that have tiny hooks and hairs that allow them to grab onto wool fibers. Once latched on, they can efficiently gnaw through the fibers and cause damage.

Like moths, carpet beetles are often introduced into the home via infested used furniture, fabrics, or even food products.

The carpet beetle larvae can live for up to 2 years in their larval form. This long lifespan enables them to cause major destruction to untreated wool over time.

As they feed, the larvae leave behind patches of missing wool fibers, creating a moth-eaten appearance. These damaged patches may expand in size if the infestation continues.

How to Prevent Them?

The key to avoiding pesky holes in your fine Merino wool garments is preventing pests from accessing them in the first place. Here are some tips to keep your wool safe from hungry bugs:

  • Store wool clothing in cedar chests or garment bags – cedar repels moths.
  • Use protective cloth bags or sealed containers for storage. This deprives moths and beetles access.
  • Have wool clothing professionally cleaned before storage as food stains can attract pests.
  • Inspect wood furniture, floors, and baseboards for signs of infestation – treat promptly if found.
  • Vacuum and clean frequently to remove larval food sources like hair, lint, dust.
  • Place sticky traps in closets and drawers to monitor bug populations.
  • Avoid storing wool items in attics, garages or basements where pests thrive.

2. Normal Use Causing Friction Damage

The individual wool fibers that make up a piece of merino fabric have an outer protective layer called the cuticle. This cuticle is made up of overlapping scales that run along the length of each strand of wool.

When merino wool garments rub against themselves or other surfaces, the friction wears away and damages these outer scales.

As the scales lift and break down, the inner wool fibers become exposed and more prone to continued abrasion damage.

Specific areas of merino apparel that experience repetitive friction during normal wear are particularly vulnerable to this effect.

For example, the inner thighs of pants, sleeve cuffs, collars, and waistbands commonly thin from abrasion over time. As the wool fibers weaken, stress points can begin to form where the fabric is the most thin and damaged.

In addition, the more frequently and vigorously you wear your Merino wool garments, the higher the chances of experiencing friction damage.

Activities such as hiking, running, or simply wearing your favorite sweater every day can accelerate the wear and tear process.

When friction forces are applied through activities like walking or rubbing against chairs, the scales get disturbed and start to stick out from the fiber.

Repeated disturbance causes more and more scales to raise up. This leads to broken and cracked cuticles, exposing the inner fiber.

With the protective cuticle layer damaged, the inner wool core becomes prone to breaking. The friction then causes individual wool fibers to fracture and shear off, leaving behind thin spots and holes.

Furthermore, frequent washing and drying can also contribute to friction damage. Aggressive washing cycles, high temperatures, and rough handling can cause fibers to rub against each other, resulting in weakened areas that may eventually give way to holes.

How to prevent?

To minimize the risk of friction damage and prolong the life of your merino wool garments, follow these expert tips:

  • Gentle Handwashing: Handwashing is the preferred method for cleaning merino wool. Use a mild detergent specifically formulated for wool and lukewarm water. Gently agitate the garment without rubbing it excessively. Rinse thoroughly and avoid wringing or twisting the fabric.
  • Drying with Care: After handwashing, gently squeeze out excess water and lay the garment flat on a clean towel to dry. Avoid hanging or wringing the wool, as this can stretch and distort the fibers. Reshape the garment if necessary while it is still damp.
  • Layering and Protective Measures: Consider layering your merino wool items with a soft, breathable barrier, such as a cotton undershirt, to minimize direct contact with abrasive surfaces. Additionally, be mindful of sharp objects or accessories that could snag or create friction against your woolen garments.

3. Metal Parts like Zippers Abrading Fabric

When metal parts rub against the fabric repeatedly, they gradually wear down the fibers. The friction breaks the wool fibers little by little until a hole forms.

This often happens in areas where the garment naturally rubs and folds, like near zippers, pocket openings, waistbands, cuffs, and collars.

The metal teeth of a zipper sliding up and down against the wool causes a lot of abrasion each time you unzip and zip up your sweater or jacket.

To understand how this happens, let’s break it down step-by-step:

First, the thin metal or plastic teeth of the zipper press into the woven wool fibers when you zip it up. The pressure applied can already start to bend and stress the fibers.

Next, when you unzip, those little metal teeth have to drag across the surface of the wool, essentially scraping against the fibers. This dragging motion pulls on the fibers and causes tiny breaks in the wool strands with each pass.

Over time, after zipping and unzipping many times, the cumulative damage causes the fibers to thin and weaken until they completely snap. When enough fibers in one area break, a tiny hole forms. As more fibers snap, the hole enlarges.

Other metal parts like snaps, rivets, and decorative hardware can also abrade wool fibers through repetitive friction.

For example, a snap pressed against wool each time you close a jacket or cardigan slowly eats away at the fibers behind it. A rivet holding on a pocket may create holes where the wool around it folds and rubs with your movements.

4. Improper Storage of Merino Wool Garments

How you fold or hang your Merino wool garments can make a big difference in their longevity. Improper folding can cause unnecessary stress on the fibers, leading to weakened areas that are more prone to developing holes.

Similarly, using wire hangers or hanging your wool garments for extended periods can stretch the fabric and distort its shape. This stretching can create weak spots in the wool, making it easier for holes to form over time.

It is crucial to fold your wool garments gently, using acid-free tissue paper to prevent creases and minimize friction. If hanging is preferred, use padded hangers to distribute the weight more evenly and avoid stretching the fabric.

How to Prevent Holes in Merino Wool?

Merino Wool is a delicate fabric that requires gentle handling to avoid damage. Its fine fibers can easily break or stretch, leading to the formation of holes. Understanding this vulnerability is the first step in preventing such mishaps.

So, here is how you can prevent holes in Merino wool:

1. Proper Washing and Drying Methods

To prevent any potential damage to your Merino Wool garments, it is essential to sort them properly before washing.

Avoid mixing them with heavy or abrasive materials like denim or clothing with zippers, as they can cause friction and lead to holes.

Instead, separate your Merino Wool items and wash them separately or with other lightweight, gentle fabrics.

Before washing your Merino wool item, always check the care label for specific instructions. Different manufacturers may have varying recommendations, so it’s essential to follow them closely.

It is generally recommended to hand wash Merino wool to avoid excessive agitation. If you prefer using a washing machine, select the delicate or wool cycle, which uses gentle movements and lower temperatures to minimize the risk of damage.

When washing Merino wool, opt for cold water instead of hot or warm. Hot water can cause the fibers to shrink or felt together, potentially leading to holes. Cold water is gentler and helps preserve the integrity of the fabric.

Use a mild detergent specifically formulated for wool or delicate fabrics. Harsh detergents containing enzymes or bleaching agents can weaken the fibers, making them more susceptible to holes. Look for gentle, wool-friendly options to protect your Merino wool.

If your Merino wool garment only has a small stain or spot, consider spot cleaning instead of washing the entire item. This minimizes the exposure to water and reduces the chances of damage.

Drying Tips

Proper drying techniques are equally important in preventing holes in Merino wool. Here are expert tips to ensure your garments maintain their integrity:

  • Always lay flat or hang to dry. Never wring, twist, or roughly handle a wet wool garment.
  • Reshape the garment and smooth seams/edges while still damp. Let air dry completely before wearing or storing.
  • Avoid direct heat sources like radiators or sunlight, which can create drying unevenness.
  • For extra care, you can lay Merino items flat between two towels and gently press to draw moisture out. Rotate towels as needed.
  • Once fully dry, store folded or hanging. Don’t leave sitting crumpled up long term.

2. Storing in Airtight Containers With Cedar/lavender

Moths hate the smell of cedar and lavender. When you store wool in an airtight container with cedar blocks or sachets of dried lavender, it helps keep moths away. The strong smells mask the scent of the wool so moths can’t find it to eat.

Cedar and lavender offer several advantages when it comes to storing Merino wool garments:

  • Natural insect deterrent: Both cedar and lavender have insect-repellent properties. They help deter moths, carpet beetles, and silverfish from infesting your woolens, keeping them hole-free. Look for ones made from real aromatic red cedar, not cedar wood chips.
  • Pleasant fragrance: Cedar and lavender emit a pleasant scent that adds a refreshing aroma to your stored woolens. Unlike mothballs, which can leave a strong chemical odor, cedar and lavender provide a natural and enjoyable fragrance.
  • Chemical-free solution: Mothballs often contain harmful chemicals that can be harmful to your health and the environment. Cedar and lavender offer a safe and chemical-free alternative, making them a more sustainable choice.

Note: You have to check the cedar or lavender every few months and replace them if they lose their scent or color.

For air-tight containers, any bin, trunk, or bag that seals tightly will work great. Look for ones that have a rubber gasket inside the lid to keep air out.

Plastic storage tubs with snap-on lids are inexpensive and work well. For extra protection, you can line them with a trash bag before putting your wool items inside. Just make sure to squeeze out excess air before sealing the container.

How to Place Cedar and Lavender?

To maximize the effectiveness of cedar and lavender, strategically place them inside your airtight containers.

You can position cedar balls or blocks near the top, bottom, and sides, ensuring that their scent permeates the entire container.

For lavender, tuck sachets or add a few drops of essential oil onto cotton balls and place them among your folded woolens.

How to store Merino Wool with air-tight containers?

First, carefully fold or roll your woolen items and place them inside the prepared airtight container.

Avoid overpacking, as this may lead to unnecessary pressure on the garments. Ensure the container is sealed tightly to prevent any entry of pests or moisture.

Find a cool, dry, and dark place to store your airtight containers. Sunlight, heat, and humidity can damage wool, so avoid areas prone to these elements, such as attics or basements.

3. Freezing Merino Wool Items Before Storage

The freezing process kills moths and other insects in their larval stage by exposing them to extremely low temperatures.

When Merino wool is frozen, the low temperatures cause the larvae to freeze, ultimately leading to their demise. By freezing your items, you can eliminate any existing pests and prevent new infestations.

How Cold and How Long?

To effectively kill insect eggs or larvae, Merino wool items should be frozen in an air-tight storage box for at least 24 hours.

For best results, freeze clothing at a temperature of 0°F (-18°C) or below. Most home freezers easily reach these chilly temperatures. Freezing for 2-3 days provides an extra safeguard against pests.

After the minimum freezing period has elapsed, remove your Merino wool items from the freezer and allow them to thaw naturally at room temperature.

Once thawed, lay them out in a well-ventilated area to air out for a few hours. This step will help eliminate any residual odors that may have developed during the freezing process.

4. Using Moth Repellent Sprays Before Storage

Moth repellent sprays act as a deterrent to keep moths away from your wool garments. These sprays often contain ingredients that repel moths, such as cedar oil, lavender oil, or natural pyrethrins.

The strong scent of these substances is highly unpleasant to moths, deterring them from approaching and laying eggs on your wool items.

So, if you dont have access to cedar or lavender blocks, you can use Moth repellent sprays.

The procedure is the same i.e. you have to ensure that your Merino wool garments are clean and completely dry. Moths are attracted to dirt and stains, so it’s crucial to remove any potential food sources before storing them.

There are various moth-repellent sprays available in the market, so it’s important to select one that suits your needs.

Look for sprays that are specifically formulated for use with wool and contain natural ingredients to avoid any potential damage to the fabric.

What are the drawbacks of using moth repellent sprays?

While moth repellent sprays can be effective in preventing holes in Merino wool, they also have some drawbacks that you should be aware of. Some of these drawbacks include:

  • Some moth repellent sprays may contain harsh chemicals that can harm your health or the environment. They may cause skin irritation, respiratory problems, or allergic reactions in some people or pets. They may also pollute the air or water if not disposed of properly.
  • Some moth repellent sprays may have an unpleasant smell that can linger on your clothes or carpets. They may also affect the natural smell of your Merino wool items and make them less appealing.
  • Some moth repellent sprays may damage your Merino wool items if not used correctly. They may cause fading, shrinking, staining, or weakening of the fabric.

Therefore, you should always use moth repellent sprays with caution and follow the directions on how to use them safely and effectively.

I would highly recommend you this Permethrin spray for Merino wool clothes. You can buy from here.

How to apply it?

To ensure that the moth-repellent spray does not cause any discoloration or damage to your wool items, it’s advisable to test it on a small, inconspicuous area first. Apply a small amount of the spray and wait for a few hours to check for any adverse reactions.

Once you have ensured that the spray is safe for use on your wool garments, hold the spray bottle approximately 6-8 inches away from the fabric.

Spray a light, even mist over the surface of the garment, ensuring that all areas are adequately covered.

Pay extra attention to cuffs, collars, and other areas where moths are more likely to target.

How often to use moth repellent sprays?

Moth repellent sprays are not a permanent solution for preventing holes in Merino wool. They can lose their effectiveness over time due to evaporation or exposure to air. Therefore, you should reapply them periodically to maintain their potency.

The frequency of reapplication may depend on the type of spray you use and the conditions of your storage area.

After applying the moth repellent spray, allow your wool items to air dry in a well-ventilated area. Avoid storing them immediately to ensure that the spray has dried completely.

Once the moth repellent spray has dried, store your wool items in a clean, airtight container or garment bag.

This will further protect them from moths and other potential damage. Additionally, adding cedar blocks or lavender sachets to the storage area can provide an extra layer of protection.

Fixing Damaged Merino Wool Items

Fixing holes in Merino wool items depends on the size of the hole.

When you notice a new hole or tear, start by taking a close look at the size and location. Small holes under 1 inch can often be rewoven so they disappear.

Larger holes or damages in high-stress areas like the elbows may require a patch. If the item is unravelling and has multiple thin spots, it may not be worth salvaging.

Now, you can perform following steps to fix damaged Merino wool items:

1. Contact the Manufacturer of Merino Wool Item

For expensive wool items, your first move should be to contact the manufacturer about warranty coverage.

Many brands guarantee their merino wool products against defects and will happily replace or repair them for you.

 For example, Smartwool offers a two-year guarantee for its socks and will replace them if they develop holes.

Check the tag for the company name and website, then reach out to their customer service team.

Simply explain the damage and ask if they have a repair or replacement policy. With proof of purchase, you may get an entirely new merino wool sweater at no charge!

2. Sew Up Small Holes

If the manufacturer won’t help, don’t sweat it! For small holes less than 1 inch wide, hand-sewing is your best DIY option. You’ll need a sewing needle, coordinated wool thread, tiny scissors, and a thimble.

First, gently fuzz up the edges of the hole so the threads mesh together. Thread your needle, tie a knot at the end, and pinch the hole closed.

Insert the needle from the inside and make very small stitches around the hole to sew it closed. Try to follow the knit pattern for an invisible fix. Finish with a knot on the inside.

3. Use Iron-On Patches

For larger holes, cuts, or weak spots, iron-on patching is an easy no-sew fix. You can find wool-blend patches online or at most craft stores.

Cut a patch slightly larger than the hole. Following the package directions, iron the patch to the wrong side (inside) of the damaged fabric. Use the heat setting for wool and press firmly. Leave it to cool completely.

The adhesive will bind the patch in place without stitches. For the best results, carefully trim away any frayed edges before applying the patch.

4. Reweave Larger Holes

The most invisible mending technique is reweaving. This involves weaving new wool yarn directly into the fabric to bridge the hole. While more time-consuming, reweaving can make damage virtually disappear.

It works best on flat areas without too much stretch. You’ll need a darning needle, wool yarn in a matching color, scissors, and a foam pad.

Stack the item over the pad. Then, working from the underside, stitch over and under the fibers, mimicking the knit pattern. Slowly reweave back and forth across the hole to fill it. Finish by gently washing and drying to fluff and reinforce the repair.

To learn more, you can read this guide on repairing Merino wool.

Some Tips for Preventing Damage of Merino Wool

The best way to keep your merino wool looking pristine is preventative care. Here are some handy tips:

  • Wash gently and lay flat to dry to avoid stretching and stressing fibers.
  • Steam wrinkles rather than ironing to protect the delicate wool fibers.
  • Avoid velcro, hooks, barbed wire, and anything abrasive that could snag.
  • For moth prevention, store wool clothing in cedar chests or with sachets of lavender or cedar.
  • Avoid excessive sun exposure which can damage and discolor wool fibers.
  • Remove pills with a fabric shaver instead of picking which can tear the weave.

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