Bird baths stay clean longer and attract robins better if you place copper pennies in them, according to a professional cleaner's garden hack shared on social media.
Robins are among the few garden birds that keep singing through the colder months and add colour to autumn gardens. Fresh water in bird baths is one of the easiest ways to attract robins, as they use it for both drinking and bathing. Even a garden with plenty of food may not keep robins around for long if there is no reliable water source.
However, bird baths don't stay clean for long, especially during the shift from summer to autumn. Algae, leaves and bird droppings will contaminate the water, and a dirty bird bath can quickly become unappealing to both gardeners and wildlife, often turning murky, smelly, or even slimy.
The copper coin hack
Professional cleaner Claire, who goes by @sisterpledgecleans on Instagram and TikTok, shared a “secret garden hack” that keeps bird bath water “fresher for longer”. She captioned the video: “Drop a couple of copper coins into your bird bath to help keep algae from taking over. Copper naturally discourages algae growth, so it helps keep the water fresher for longer and clearer between cleans.”
An “important” point the cleaner made was to use UK 1p or 2p coins dated 1992 or earlier, as those are bronze and about 97% copper, which is why “they work best”. She cautioned: “Newer coins are mostly steel with a copper coating.”
For those who don't have any copper coins, a small piece of copper wire “works exactly the same”, stated Claire.
Why the hack works
Copper found in pennies is believed to possess gentle antimicrobial qualities that can help reduce the algae and bacterial buildup that tends to flourish in stagnant water. The copper contained in pennies minted before 1992 initiates a natural chemical process in the bird bath that helps prevent algae from forming.
Bird lover and owner of The Rocky Safari, Rocky Trifari, explained: “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 bird baths.”
While copper coins won't completely stop algae from showing up, they can help keep it under control when the right coins are used and set up properly.
Cleaning pennies before use
It's best to give copper pennies a good cleaning before putting them into the bird bath, and the same goes for cleaning the bird bath itself. Adding anything to birds' water, whether for bathing or drinking, is something to take seriously.
Cleaning pennies is easy with white vinegar, salt and lemon juice, brushing with an old toothbrush. Alternatively, lemon juice with a little baking soda works. After brushing away obvious dirt until the penny looks relatively shiny, wash thoroughly and leave to dry. Only add the penny to the bird bath if a decent shine appears on the surface after cleaning.
