Clean, dry, folded and sealed. The reason each of those matters is clothes moths: their larvae digest keratin, which means wool is food, and they are drawn far more strongly to garments carrying body oils and sweat than to clean ones. Storing a merino top dirty over a summer is the most common way to lose one.
The storage routine
- Wash everything before it goes away. This is the step that matters most. Invisible body oil, skin cells and food residue are what attract moths; the wool alone is much less interesting to them.
- Make sure it is completely dry. Even slightly damp wool in a sealed container grows mildew, which stains permanently and produces an odour that does not wash out.
- Fold rather than hang. Knitwear on a hanger stretches at the shoulders under its own weight over months. Folding avoids that entirely.
- Store in a sealed container. A lidded plastic bin, a vacuum bag or a zipped fabric case. Open shelves and cardboard boxes let moths in.
- Add cedar or lavender if you like, but do not rely on it. These deter adult moths somewhat and do nothing to larvae already present. They are a supplement to cleanliness, not a substitute.
- Keep it cool, dark and dry. Avoid attics and garages where temperature and humidity swing. A closet shelf or under a bed is better.
- Check once mid-season. Catching an infestation in one garment is a much smaller problem than finding it across the whole bin in autumn.
Understanding the actual pest
The adult moth you see flying does not eat anything — it has no functional mouthparts for feeding on fabric. The damage is done by the larvae, which hatch from eggs laid directly on the material they will feed on and can spend months eating before pupating.
This matters for how you respond. Killing visible adults does very little, because the damage is already underway inside the fabric. The effective interventions are removing the food source cleanliness provides, sealing garments so eggs cannot be laid, and heat or cold treatment to kill larvae already present.
Signs of an infestation are small irregular holes, thin patches, silky webbing or tubes on the fabric surface, and gritty debris that looks like sand. Fine merino is particularly attractive to them, being soft and easy to chew.
If you find moth damage
- Isolate the garment immediately. Bag it before carrying it through the house so you are not distributing eggs.
- Freeze it. Seal it in a bag and freeze for at least 72 hours, which kills larvae and eggs at all life stages. Let it return to room temperature before opening.
- Then wash it. Freezing kills; washing removes the debris and any remaining eggs.
- Empty and clean the storage area. Vacuum thoroughly, including cracks and the underside of shelves, and dispose of the vacuum contents outside.
- Inspect everything that was stored nearby. Infestations rarely stay in one garment.
Folding, hanging and creases
Fold along existing seams where possible, and refold along different lines if garments are stored for more than one season. Permanent creases form where a fold stays under pressure for a long time, and heavy items stacked on light knits accelerate that.
Heavier merino sweaters and knitwear should go at the bottom of a stack, lighter base layers at the top. Vacuum bags are excellent for space and acceptable for wool provided the garments are completely dry, though they do compress loft — allow a day of hanging to recover before wearing.
Cedar, mothballs and what actually works
Cedar blocks and lavender sachets are mild deterrents to adult moths looking for somewhere to lay. They do nothing to larvae already in a garment, and cedar loses its aromatic oils within a year or so unless the surface is sanded back. Treat them as a small supplementary measure.
Traditional mothballs work, because they are a pesticide that sublimates into a toxic atmosphere inside a sealed container. That is also why they are worth avoiding in living spaces — the active compounds are hazardous to breathe, the smell permeates fabric and lingers for a long time, and the container has to stay genuinely sealed for them to do anything at all.
Pheromone traps are useful for monitoring rather than control. They catch adult males and tell you an infestation exists, which is worth knowing early, but they will not clear one on their own. Cleanliness plus sealed storage remains the effective combination.
Short-term storage through the season
Between wears, the rule is different: air before putting anything away. A base layer worn once and folded straight into a drawer traps residual moisture and body oil, which is how a drawer starts to smell and how the fibre picks up odour it will not release.
Give a worn garment several hours hanging in moving air, then fold it. Merino socks and underwear skip this entirely — they go to the wash after every wear regardless, and airing a worn sock achieves very little.
Our guides to how often to wash merino and preventing pilling cover the in-season habits that keep garments in condition between storage cycles.
Related merino guides
Sources
- Woolmark: how to store wool clothes
- University of Kentucky Entomology: clothes moths
- Icebreaker: how to care for merino wool
Image: Merino Mart catalogue. Browse base layer tops.