By Bed Threads Bedding 14.10.2026

[Preview] The Truth About Leaving Laundry in the Washing Machine Overnight

We've all been guilty of this at some point or another, but here is what you need to know about leaving your wet washing to sit overnight...

We've all been there – we head to bed or leave the house forgetting that we've left wet laundry in the washing machine, dryer, or basket. Whether it's been a couple of hours or an entire day/night, we’re left wondering whether it needs another wash or can go straight out to dry. After all, we don't want our clothes and linen bedding to smell musty or develop mildew, especially when it’s bedding you sleep in all night. It's also a waste of water and electricity to unnecessarily put on a load of washing for a second time.

Let's take a look at how long you can leave your wet laundry in the washing machine before you need to give it another wash, and what you need to do if it's been left for too long and has started to smell.

How long can you leave wet washing for?

If damp clothes or bedding have been left in the washing machine or a basket for 8-12 hours, we recommend giving it another wash. If they’ve been sitting for more than 12 hours, they’ll likely need another wash. Bacteria and mildew can begin to grow on the laundry, causing it to smell.

According to a medically reviewed article published on Healthline, "Mildew is a fungus that thrives in warm, damp environments, so your washer is an ideal incubator", which can lead to symptoms such as a stuffy nose, wheezing, and red or itchy eyes or skin.

If you're someone who forgets their laundry regularly, it's worth using an unscented or gentle detergent that doesn't mask signs of mildew to help you better decipher whether it needs a second wash.

How to decide when to rewash laundry

If your wet laundry has been sitting for under 12 hours and you're unsure whether it needs another wash, you can do a smell test of the items to see if there's a distinct mildew odour (a musty and often pungent smell).

If not, it's likely safe to just hang them out to dry or pop them in the dryer. If you notice a white, grey or yellow fluffy or powdery growth on your laundry, it absolutely needs another wash.

How to wash your linen

You can either hand or machine wash your linen – always separately – and always with lukewarm or cold water. Linen is ultra-absorbent, so we advise that you launder any stains while they are still new to avoid permanent damage. For this very reason, use plenty of water when both washing and rinsing your linen to prevent stain absorption.

A gentle detergent will work well, especially when used in combination with an oxygen-type bleach instead of a chlorine-based alternative for pure white linen to minimise the risk of discolouration.

If your linen has a mildew smell to it, the best course of action is to wash it in a cycle with one cup of vinegar and then a cycle with one cup of baking/bicarb soda. If possible, it's a good idea to air dry your linen in the sun as the ultraviolet rays have disinfecting properties that can help kill any remaining bacteria in the laundry.

How to wash your washing machine

The idea of washing your washing machine may sound funny, but it is something you should do every now and then. It's especially important to not forget to inspect and clean your washing machine if the source of the mildew is coming from the seal. To do this, simply run an empty, regular cycle on hot, using two cups of white vinegar instead of detergent. The hot water and vinegar combo will fight any mould, mildew, and everyday gunk.

Tips for remembering your washing

We're all guilty of forgetting our washing from time to time, but if you have a habit of doing it weekly – no judgement here – it's worth trying one of the below tricks to help you remember.

Set a timer on your phone.
Use the timer on the machine.
Get in the habit of washing at the same time each week.
Take immediate action as soon as you hear the washing machine go off rather than leaving it for what you think will be a few minutes.