UK birdbath owners are being encouraged to drop a 2p coin into their birdbaths this summer to prevent algae growth and attract robins and other birds. The copper from the coin acts as a natural biocide, keeping the water clean and safe for wildlife.
Why Copper Works
Birdbaths quickly become grimy and develop algae, especially in warm weather. Copper ions released from the coin inhibit algae and bacterial growth, maintaining fresh water for birds. Experts at Gardening Know How describe copper pennies as "one of the cheapest and easiest ways to keep your birdbath clean so you can attract more birds to your garden."
Rocky Trifari, bird enthusiast and owner of The Rocky Safari, explains: "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."
Which Coins to Use
One or two-penny coins minted before 1982 are recommended, as they contain higher copper content. Coins should be checked for rust or corrosion before use. Chris Bonnett, founder of GardeningExpress.co.uk, advises: "If you find your birdbath quickly attracts algae you can actually place a 2p coin at the bottom once it's cleaned to help slow down the growth of it. This means you might be able to go a bit longer before having to give it another clean."
Important Precautions
Excessive copper exposure can harm smaller bird species, so only a limited number of coins should be used. This trick does not replace regular cleaning. Bonnett emphasizes: "A clean birdbath is crucial in preventing the spread of diseases so if you haven't used yours in a while give it some care before filling it up with water." Regular rinsing and scrubbing remain essential, especially during summer when warmer temperatures accelerate contamination.
By adding a copper 2p coin to your birdbath this summer, you can help maintain a clean water source for birds, particularly during heatwaves when wildlife seeks safe hydration.
