The Simple Penny Trick That Makes Your Bird Bath Safer for Wildlife This Summer – Gardeners Swear By It
Keep visiting birds happier with this time-saving hack
A dirty bird bath can quickly become unappealing to both gardeners and wildlife, often turning murky, smelly, or even slimy in warm weather. However, a penny or two placed in your bird bath can help slow the build-up of algae and grime, keeping the water cleaner for visiting birds.
This is thanks to the small amount of copper released into the water. But, it is a supporting hack rather than a standalone solution. Bird baths still need frequent cleaning, rinsing and scrubbing to stay safe, especially in summer when heat accelerates stagnation and contamination.
Here, avian experts explain how this copper coin trick may help keep bird baths fresher for longer, what types of build-up it can help reduce, and why regular cleaning remains essential. It’s a timely addition to your garden routine as warmer weather draws more wildlife in search of a drink.
Article continues belowWhat is the Copper Penny Hack?
This hack is a super-easy trick to implement in your garden, and involves placing a small number of pennies around the deep base of your bird bath.
The copper in pennies is thought to have mild antimicrobial properties, which may help discourage some of the algae and bacterial growth that thrives in standing water.
It's far cheaper than adding a purification disk into the bottom of your bath, like this copper bird bath purification disk available on Amazon (though it's a great alternative), and you may already have the coins to hand needed for the job.
The copper present in pre-1982 one or two-penny coins triggers a chemical reaction in your bird bath's water that acts to naturally fend off the development of algae: a common slimy substance that leaves sticky, unsightly residue on bird baths over time.
Rocky Trifari, bird enthusiast and owner of The Rocky Safari, shares a bit more about how and why this hack works. 'Copper is a natural biocide with properties that interfere with the biological processes algae and other microorganisms rely on.
'When copper ions leach into the water, they promote an environment that discourages the growth of green algae, one of the main causes of that slimy, dirty water found in birdbaths.'
Although placing copper coins in your bird bath won't prevent algae from ever being able to create an eyesore in your wildlife garden, it will be largely limited if the coins you're using are effectively placed and prepped.
Rocky Trifari, is the bird enthusiast behind The Rocky Safari, where he has been documenting his wildlife encounters and birding adventures for over a decade.
Prepping your pennies
Before placing any pennies in your bird bath, give them a thorough clean using natural methods and check carefully for any signs of rust or corrosion.
Avoid using harsh chemicals, as residue can be harmful to birds, and damaged or degrading coins can introduce unwanted contaminants such as metals or coatings into the water, all of which are best avoided in any bird baths mistakes.
Monika Sangar, an avian nutrition specialist, explains: 'Birds drink and bathe in bird bath water, so prolonged or excessive exposure to dissolved copper could pose a health risk, especially to small species.'
She adds: 'For this reason, it’s best to only use a few coins at maximum in a larger bath, and to always clean the bath in addition to using this hack. Adding fresh water daily for your birds is a must, too.'
Even with this trick, regular maintenance remains essential. In warmer weather especially, stagnant water can quickly become unappealing to wildlife and may encourage algae growth or bacteria.
If your bird bath is on the larger side, introducing gentle movement can also help keep it fresher for longer. For example, a small solar-powered fountain pump, such as this one from Amazon can improve circulation and prevent the water from sitting still on hot days.
To clean your pennies safely, Monika suggests following the simple at-home methods below, using ingredients you likely already have in your pantry:
- Vinegar and salt: 'Soak your pennies in a mixture of white vinegar and salt for a few minutes. Then, gently scrub each coin with a soft toothbrush or cloth. Finally, rinse the coins thoroughly with clean water and dry completely.' This white vinegar from Walmart is less than two dollars.
- Lemon juice and baking soda: 'Rub each coin with lemon juice and a pinch of baking soda. Rinse and dry well.' The Arm & Hammer pure baking soda from Walmart, is budget-friendly choice with great reviews.
If your copper coins are now clean and show no signs of rust, corrosion or going green, they are ready to place in your bird bath.
'These coins can be left in the bird bath indefinitely, or until you notice they've become tarnished or corroded,' says Rocky. 'Though replacing them seasonally is a good practice.'
Monika Sangar holds a Master of Science in Molecular Biology and is a dedicated Avian Nutrition Specialist with over 14 years of hands-on experience rescuing and rehabilitating parrots. As the founder of PDS nonprofit and Owner of PDS Parrot Shop, she combines scientific knowledge with practical expertise to create enrichment-focused bird toys and species-appropriate diets. Her work emphasizes evidence-based care, behavioral enrichment, and long-term wellness for companion parrots. She is also an author who wrote, The Science of Avian Nutrition.
Hoe Long Does it Take to Work?
This simple hack should begin working fairly quickly, provided your pennies are properly cleaned and made from copper.
'You will likely begin to notice a reduction in algae buildup within a few days of placing copper pennies in the birdbath,' says Rocky.
He adds: 'The effect is gradual, not instant, and bird bath winter care will still be required. As the copper ions slowly accumulate in the water over time, your water will stay clearer between cleanings.'
That said, it’s important not to expect a completely maintenance-free solution. Regular emptying and scrubbing are still essential for keeping bird baths safe and hygienic throughout the year.
For best results, start with a clean slate. A long-handled, stiff-bristled brush designed for bird baths or outdoor water features works particularly well, helping you reach corners and remove any existing dirt without damaging the surface. This brush for bird baths from Amazon is a great option for the job.
What to Shop
Resin bird baths are among the easiest to keep clean due to their non-porous nature. Algae also has a hard time sticking to the sides.
You can use this glass design as a bird feeder or a bath, and will add a whimsical, artisan flair when suspended from a tree near your patio.
If you're looking for something more rustic, a metal bird bath such as this rust-proof one will be unobtrusive in your yard.
While it’s not a replacement for regular cleaning, this simple trick can make maintenance easier and help create a healthier drinking and bathing spot in your garden.
If a bird bath has always been a dream addition to your yard, why not consider making your own? There are plenty of inspiring DIY ideas for welcoming birds into your yard, and it would be the perfect pre-summer project.
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