Storing Knitwear Between Seasons: Moths, Folding and Cedar

Wool moths do their damage in the months you are not looking, which is exactly why the drawer wins. A sweater develops two pinprick holes in October and a fist-sized one in March, and the owner blames the closet’s air quality. The truth is blunter: the larvae hatched in the spring drawer, ate through the summer, and the sweater was food the day it went in. Storage is not an afterthought to knitwear care. It is the difference between a ten-year sweater and a three-year one.

The moth calendar

The clothes moth lays 40 to 50 eggs on keratin, the protein in wool and cashmere; silk and hair carry the same protein, and the eggs hatch at room temperature within a week or two. Larvae feed for six to ten weeks, and the feeding damage is what you find later. Two facts do all the work here.

First, adult moths do not eat; the larvae do, so the moth you swat is not the moth that costs you the sweater. Second, larvae want more than pure keratin: the salt left by perspiration attracts them, and food stains or body oils on any fabric do the same, which is why a breakfast-stained cotton tee can host an infestation that spreads to the cashmere beside it. The infestation moves by adjacency. It ends with the drawer being emptied.

Clean before storage

The single rule that prevents most losses: nothing goes into storage unwashed, not even worn once. Perspiration and invisible food residue are larvae attractants, and a garment worn for one dinner carries both. Follow washing wool at home for the cold-water hand wash, or dry-clean what you will not wash, and let everything dry fully before it goes into a box; damp wool stored warm invites mildew as well as moths. Clean storage also starts the season right for cashmere care such as de-pilling, since pills give larvae more fiber ends to grip.

Drying has its own rule: flat, on a towel, away from the radiator. Hanging wet wool to hurry things along is how stored knits come out of the box pre-stretched. A garment that feels dry at dusk is often still damp at the seams, so give it until the next morning before any box closes.

Fold, don’t hang

Knits stretch under their own weight, and the stretch is permanent: gravity pulls the shoulder line down and out, leaving hanger bumps that no steam restores.

Fold along the side seams rather than down the middle, stack no more than four or five deep, and give the heaviest pieces, the 8-ounce fishermen’s knits, the bottom of the stack. Rotate the stack at least once a season. Folding is also when you inspect: the larvae live on the undersides and at the collar, so a 30-second look at each piece per season catches damage at the pinprick stage.

The fold itself is simple: sleeves tucked behind the body, the piece folded in thirds along the seam lines, so no hard crease runs across a cable pattern or a printed front. If the stack sits in daylight, a cotton bag over it spares the dyes; sun fades the shelf-facing sweater while the ones underneath stay dark. That is one more reason the lidded box outperforms the open shelf.

Choosing the container

The container decides which threats reach the wool. An airtight lidded box or a sealed cotton bag does double duty: it starves larvae of air exchange and blocks new moths from landing a fresh round of eggs on the stack. A loose-woven laundry bag blocks nothing that matters, because moths move through open weave without slowing down. Vacuum-sealed bags earn their keep for a single off-season, but long compression flattens the loft of a knit, and loft is what insulates; a sweater kept compressed for a year needs washing and a rest before it looks like itself again. Whatever container you pick, wool goes in clean and fully dry. The box is the last step of the routine, not the first. Thin plastic bags and cardboard give determined larvae something to chew through, which is why rigid lidded boxes and sealed cotton bags are the storage-grade options rather than the delicate ones.

Cedar, lavender and the truth about both

Cedar and lavender repel only while aromatic, and both fade faster than a storage season. Cedar’s volatile oil evaporates within months; the fix is mechanical — a light sanding each spring releases fresh oil. Neither kills larvae at closet-open concentration, so treat both as one layer among several, never as the plan. The layers that work: airtight storage, which starves larvae of air exchange and blocks new moths; breathable cotton garment bags, which block moths while wool rests; and cold, the freezer cycle that kills every life stage. Seal, freeze, thaw slowly, then store.

The freezer cycle, start to finish

Cold does what cedar cannot: it kills every stage of the moth. Seal the garment in a plastic bag, press out the spare air, and freeze at minus 18 degrees Celsius for 72 hours, the setting of a household freezer. Then leave the bag closed on the counter until the wool returns to room temperature. The slow thaw matters — opening the bag early condenses moisture onto cold fiber, and damp wool brings mildew into the same box you just protected. Once the piece is dry to the touch, it goes straight into the sealed container, so no adult moth reaches it on the way to storage. A borrowed coat or a suitcase that spent time in a moth-prone closet gets the same treatment before it enters yours.

What a sealed season looks like

Washed, fully dried, folded, in a lidded box or sealed cotton bag, with fresh cedar inside, in a cool dark place. Check at mid-season for pinholes and grainy dust, the frass larvae leave behind; reading a sweater label tells you what wool you are protecting, but only inspection tells you whether it held. A missed spot shows up as grit in the folds of the box before it shows as holes; larvae feed where they hatched, so the evidence lands under the piece that carried the eggs. Empty the box when you check rather than lifting pieces out one by one. Moths find a drawer that nobody opens. So open it, twice a season, and keep what survives the third year.