September draws more birds like robins and blackbirds into gardens as they search for clean water while natural sources begin to dry up. Keeping your birdbath clean in autumn is especially important, as falling leaves, berries, and debris can contaminate the water and encourage algae to grow.
Birdbaths can be tricky to maintain without regular scrubbing, but wildlife experts at Birdfy say it is easy to keep them clean as long as you avoid using outdated advice like copper pennies in the water. One expert said: “Birds can be sensitive to the accumulation of copper in their systems, leading to health issues such as liver damage and gastrointestinal distress.
“The risk of toxicity increases significantly if copper concentrations exceed safe levels, which could potentially happen over time with the addition of copper pennies.”
Why should you never put copper pennies in a birdbath
It is common for gardeners to suggest putting pennies in a birdbath, since copper has antimicrobial properties that can help reduce algae and bacteria in water.
This practice can be toxic to birds, as not only can copper build up in their systems, but most modern pennies contain zinc, which is highly poisonous to birds even in small amounts.
Dropping pennies in a birdbath does not provide enough copper to prevent algae growth, so it will not keep a birdbath clean and instead makes the water unsafe for wildlife.
However, there is a safe and natural way to keep algae out of a birdbath, as you simply need to add some underwater plants to the water instead.
What plants keep algae away from birdbaths
Watercress is one of the best aquatic plants to have in a birdbath as it naturally antibacterial while being editable for birds, so you help support wildlife without much extra work.
Duckweed and hornwort are safe for birds to eat and help reduce algae by competing with it for oxygen. Additionally, duckweed floats on the water’s surface, blocking sunlight and preventing algae from growing.
Make sure to avoid overcrowding the water as birds still need plenty of space to shrink, and you will also need to remove any decaying plant material otherwise it will simply cause algae to grow back.
However, having aquatic plants in your birdbath is the most effective way to keep algae away for long periods of time while helping local birds stay safe and healthy as the weather gets colder.