Short answer: mould on fabric is two problems, and most attempts fail because they only solve one. You have to kill the organism and remove the pigment it left behind. Brush the growth off outdoors while dry, then soak in oxygen bleach, wash at the hottest temperature the fabric allows, and dry in direct sunlight, which bleaches the residual stain better than anything you can buy. If it keeps coming back, the fabric is not the problem: something is staying damp.
First, outdoors and dry
Do not start by wetting it. Wet mould smears into the weave and spreads spores through the water, which is how one towel becomes a whole load.
- Take it outside and let it dry completely if it is damp.
- Brush the surface growth off with a stiff brush, downwind, away from the house.
- Vacuum the item if it is large and cannot go in a machine, then empty the vacuum outside.
- Then move on to the wet treatment below.
Treatment by fabric
| Fabric | Treatment | Avoid |
|---|---|---|
| White cotton and linen | Oxygen bleach soak 4 to 6 hours, then wash at 60 °C, then sun | Nothing much. These are the easy ones |
| Coloured cotton | Oxygen bleach, cooler and longer, then the hottest wash the label allows | Chlorine bleach, which strips the colour too |
| Synthetics | White vinegar soak 1 hour, then a 40 to 60 °C wash | Very hot water, which sets the stain into the fibre |
| Wool and silk | Brush dry, air outdoors, then a cool hand wash. Specialist clean if it persists | All bleaches and hot water. These destroy protein fibres |
| Canvas and outdoor fabric | Scrub with white vinegar solution, rinse, dry fully in sun, then reproof | Detergent, which strips the waterproof finish |
| Shower curtains | 40 °C with two towels for friction, plus oxygen bleach | Tumble drying. Hang to drip dry |
| Leather | Wipe with a barely damp cloth, dry slowly, then condition | Soaking. Water ruins hide faster than the mould does |
The oxygen bleach soak
Dissolve oxygen bleach fully in hot water first, then top the basin up to the right temperature for the fabric. Submerge the item completely, because anything above the water line develops a tide mark. Four to six hours, or overnight for heavy staining. Then wash as normal. Expect to repeat it once; mould pigment rarely leaves in a single pass.
The vinegar method
For synthetics and anything you would rather not bleach: 240 ml of white vinegar per 4 litres of warm water, one hour, then a normal wash with a full dose of detergent. Vinegar kills a good share of mould and deodorises well. It is weaker than oxygen bleach on the stain itself, so it suits fresh growth better than old.
Sunlight, which is the underrated step
Dry the item in direct sunlight while it is still damp. Ultraviolet light bleaches the residual pigment and kills remaining spores, and on white cotton it routinely clears a shadow that two wash cycles left behind. It costs nothing and it is the single most effective finishing step. The only caveat is that it fades coloured fabric too, so keep colours in bright shade and save full sun for whites.
Why it keeps coming back
If mould returns on the same items, the treatment is not failing, the conditions are. Mould needs moisture, and removing the moisture is the only permanent fix.
| Where it returns | Usually | Fix |
|---|---|---|
| Towels and bath mats | Hung folded on a hook, never drying fully | Spread full width on a rail. A towel needs air, not a hook |
| Inside the washing machine | Biofilm in the door seal and drawer | Monthly 90 °C empty cycle, scrub the seal, leave the door ajar. See cleaning a washing machine |
| Clothes in a wardrobe | Humidity above 60 percent, or clothes put away damp | Moisture absorber, airflow, and nothing stored damp. See the wardrobe guide |
| A load left in the drum | Wet laundry sitting for hours | Rewash. An alarm on your phone costs nothing |
| Tents and outdoor gear | Packed away damp | Always dry fully before storing, even if it means setting it up indoors |
| Drying indoors | Two litres of water per load going into the room | Dehumidifier, not radiators. See how to dry clothes properly |
| A basement or garage | Ambient damp | Do not store textiles there, or run a dehumidifier permanently |
What to be careful about
- Never mix chlorine bleach with vinegar or ammonia. The combination produces toxic gas. Choose one treatment and rinse thoroughly before trying another.
- Work outdoors or with windows open, and wear gloves. Disturbing mould releases spores.
- Do not wash mouldy items with clean laundry. Wash them alone, then run an empty hot cycle before the next load.
- Heavy growth on upholstery or a mattress is usually a job for a professional, or for replacement. Surface treatment does not reach what is inside the foam.
- Black spotting that has eaten into the fibre has weakened the fabric permanently. You can remove the colour; you cannot restore the strength.
- If mould is growing on walls as well as fabric, the building has a damp problem and the laundry is a symptom.
Frequently asked questions
How do you get mould out of fabric?
Brush the growth off outdoors while the fabric is dry, then soak in oxygen bleach for four to six hours, wash at the hottest temperature the fabric allows, and dry in direct sunlight. You have to kill the organism and remove the pigment separately, which is why single-step attempts usually fail.
Does vinegar kill mould on clothes?
Partly. White vinegar, around 240 ml per 4 litres of warm water for an hour, kills a good share of mould and deodorises well, which makes it the right choice for synthetics and anything you would rather not bleach. It is weaker on the stain itself, so it suits fresh growth better than old.
Will mould stains come out completely?
Often, on white cotton and linen, especially with an oxygen bleach soak followed by sunlight. On coloured fabric and on old growth a shadow may remain. Where the mould has eaten into the fibre, the fabric is permanently weakened even once the colour is gone.
Can you put mouldy clothes in the washing machine?
Yes, but brush the growth off outdoors first and wash them alone, never with clean laundry. Run an empty hot cycle afterwards. Washing mould straight in spreads spores through the water to everything else in the drum.
Why does mildew keep coming back on my towels?
Because they never dry fully. A towel folded over a hook stays damp in the fold, which is all mildew needs. Spread towels at full width on a rail, wash them at 60 °C periodically, and check the machine's door seal, which is the other common source.
How do you get mould out of a shower curtain?
Machine wash it at 40 °C with two old towels for friction and oxygen bleach added, then hang it straight back up to drip dry. Never tumble dry a plastic or coated curtain. If it is heavily spotted and old, replacing it is usually the better answer.
Is it safe to use bleach on mould?
Oxygen bleach is safe on most fabrics and is the better default. Chlorine bleach strips colour, damages elastane and technical finishes, and must never be mixed with vinegar or ammonia, since the combination produces toxic gas. Work with ventilation and gloves either way.
