4 secret summer 'mold magnets' that experts urge households to get rid of right now from basements

For many, it’s a mysterious realm of dusty relics and forgotten dreams. But a cluttered basement without climate control isn't just an eyesore – it can be a breeding ground for mold and unnecessary stress.

Here, home organization pros reveal the four things you're better off relocating or getting rid of in the summer when humidity is high.

Take control of this space and banish mold risks with a timely basement organizing session.

1. Cardboard boxes

Cardboard boxes often migrate to the basement after a house move or a large online purchase, and never leave. But they're a prime target to absorb high moisture with their porous structure.

Interior designer Lara Nancy Cupido, of LN Studio, says, 'Cardboard is basically a mold magnet. Trust me – even if your basement seems dry, humidity spikes will turn those boxes into a soggy, green nightmare.

'Instead, transfer keepsakes into sealed plastic bins, then let go of anything that’s been boxed for more than two moves ago.'

Ben Soreff, professional organizer at House to Home Organizing, agrees. He says, 'Cardboard boxes create the perfect 'out of sight, out of mind' item.

'People see the basement as a make-it-go-away space, and because you can't see what's inside, cardboard boxes are a popular choice. But they can gather mold, and at some point, the basement will flood or a pipe will burst – usually while you're on vacation!'

Soreff and Cupido advise opting for clear, weathertight, plastic bins, such as IRIS USA Stackable Plastic Storage Bins from Amazon.

Cupido adds, 'These bins lock out moisture and stack neatly. No more collapsing boxes or moldy surprises.'

2. Old paint cans

That half-empty can of 'Sherwin-Williams Pure White' from a renovation five years ago? It's likely dried up, separated, or utterly useless now. Old paint cans take up valuable space, and if they're not sealed properly, they can leak, creating a sticky, messy, and potentially mouldy problem.

Cupido says, 'Paint cans rust and leak over time, filling your basement with toxic fumes and sticky splatters. If it’s latex paint and nearly full, pour it out to dry, then toss it in the trash once it’s solid. If it’s oil-based, take it to a hazardous-waste drop-off. You’ll be amazed how many people forget this step and end up with a nasty spill.'

Cupido recommends a paint can opener such as the Hyde Paint Can Opener from Amazon. She adds, 'This will get even the nastiest, rusted lids off without bending them. Perfect for deciding if that bottom layer of paint is still usable or truly junk.'

Our expert guide 'Does paint go bad?' explains exactly how and why paint can expire, plus what to do about it.

3. Outdated holiday decor

Many basements are home to bags and bins of holiday decorations that are dirty, tangled, or haven't seen the light of day in years.

This can make them a prime target for mold, especially any with fabric elements, such as bows and ribbons. There are other problems, too.

Cupido says, 'Broken ornaments and frayed cords aren’t just eyesores – they’re fire hazards and accident risks. Sort through your holiday bins every year, and if you haven’t used it in two seasons, say goodbye.

'For those fragile ornaments that you do decide to keep, opt for compartmentalized boxes so they don’t get crushed.'

ProPik Ornament Storage Boxes with Dividers, available from Amazon, provide five layers of safe storage and have handles for easy relocation.

Using a lidded bin will help to keep moisture away, too.

Consider also whether vertical storage can help keep delicate items in better condition, as well as providing easier access to your possessions.

The Alden Design 5-Shelf Adjustable Storage Shelf Unit from Walmart and the Seville Classics 5-Tier Wire Shelving with Wheels from Amazon are two reliable options.

4. Suitcases you'll never use

Suitcases take up a considerable amount of space. But how many do you really need?

Toner says, 'Hard-sided luggage may eventually crack when stored in spaces with fluctuating temperatures, and fabric ones become a cozy nesting spot for spiders and mice. Plus, we’ve seen mold and musty smells ruin perfectly good bags just from sitting too long.

'Instead, keep only your go-to travel bags. Donate extras to foster care organizations or shelters; they’re often needed for transporting personal items.'

Toner recommends Cedar Space Cedar Blocks from Amazon, adding, 'For suitcases you do intend to keep and use, toss these in to prevent musty smells.'

Meet the experts

Lara Nancy Cupido

With over 15 years of design and construction management experience, Lara blends practical solutions with beautiful aesthetics. She studied architectural theory and fine art history at the University of Toronto and earned her master’s in interior design from the Scuola Politecnica di Design in Milan.

Ben Soreff

With more than 15 years' experience in the industry, Ben created House to Home Organizing to help homeowners get their spaces looking beautiful and functioning too. He regularly provides expert comment for Homes & Gardens, as well as other industry-leading magazines.

So there you have it – four items in your basement you should get rid of right now to stop that pesky summer humidity from creating a hidden problem out of sight.

Next, check out the things people with nice-smelling basements always do and the items to never store in yours.