As the freezing weather draws closer and closer in, it gets tougher and tougher for your wildlife to thrive.
We’ve recommended tactics like feeding hedgehogs, leaving leaf piles on your lawn, and even keeping off your own grass as methods to help your garden (and everything in it) survive the colder months.
But now, a new request has been made of UK gardeners; “In winter, leave a rubber ball floating on the pond... that way, any animals in the pond will have oxygen,” the RSPCA says.
Of course, it doesn’t have to be a rubber ball; a tennis ball does a great job. But why does it work, and what’s the best method?
Tennis balls can help to give wildlife drinking water
The issue is not, as I’d assumed it would be, that the ice made the water too inaccessible and hard for beasties to access.
Nor is it, as is the case with lake-bound fish, that the lack of gaseous exchange deprives your pond’s fish and insects of oxygen; “Don’t worry too much about your pond freezing over, as algae and pond plants continue to produce oxygen even in winter,” Wild About Gardens says.
The problem comes instead with the wildlife who want to access your pond’s water for something to drink. After all, “It is also important to keep the water topped up during the chilly winter months as sources of water can become frozen and more difficult to find,” The Wildlife Trusts shared.
In this case, “you could leave a small ball on the surface [of your pond] overnight, removing it in the morning to allow access to the water,” Wild About Gardens suggests.
It’s not the only possible use of the ball
Another theory is that the ball will move around according to the breeze, helping to break up any impending ice.
“In a small pond, the tennis ball will prevent the pond from freezing because it will keep the water moving constantly,” Lindsey Hyland, founder of Urban Organic Yield, told Gardening Etc.
But there are downsides ― “In a larger pond, the ball won’t have as much of an effect because there is too much water for the ball to move it around efficiently.”, Hyland warns.
So, the tennis ball trick works wonders for smaller ponds and birdbaths. But if you’re in a truly cold area, the tennis ball might not be enough ― consider investing in a pump if you’re worried about the oxygen levels in your water.
The trick of removing a tennis ball from a frozen pond is failsafe, however; perhaps this year your gardening gloves might have to double as baseball mitts.