Ponds are a great addition to any plot, adding interest and dimension whilst welcoming a huge range of garden wildlife. It’s a real delight to spot frogs, tadpoles, fish and even bird life enjoying themselves in and around the pond all year round! Any proud established pond owner will know that they involve a little bit of work in order to keep them looking great and providing a healthy environment for wildlife, and there are a few times in the year when a pond will need a good overhaul.
It’s important to give your pond a good autumn clean, because at this time of year the water tends to be full of fallen leaves and organic matter from the changing seasons. There’s also likely to be some leggy invasive plants that have got a bit ahead of themselves over summer. If organic matter is left in your pond it will rot, absorbing oxygen and releasing harmful gases.
Leaf it out
Using a net, or rubber-gloved hands, scoop out as much of the fallen leaf matter and vegetation as you can (this can be added to your compost heap – read my article on home composting here). Trim back any excess waterweed and plants around the side of the pond, particularly if it’s looking yellow or slimy. It’s important not to remove all of the vegetation, however, as wildlife shelters and feeds here. Blanketweed may be covering the surface of your pond, in which case it can be gathered together with a bamboo cane or a fallen stick, and disposed of.
Feed the fish
As water temperature drops, the metabolism of your pond fish will drop too. This means they won’t need as much protein in their diet, so you can switch over to a fibre-rich food such as winter wheat germ as soon as the water consistently registers lower than ten degrees.
Test the water
Literally! Pick up a cheap pond water testing kit and make sure the levels are as they should be,
in order to promote a healthy growth environment for fish, wildlife and plants. If you’re registering excess nitrates, address this promptly with a series of fresh water changes. This will ensure that your water is in good shape for the potential challenges that a winter freeze might bring.
Break the ice
It’s very rare that a normal-sized pond will totally freeze (in the UK, anyway), but the surface may freeze in a really cold snap. You might find that floating a small plastic ball on the surface delays the process, but if it suddenly freezes it’s a good idea to crack a small hole or two in the ice to stop toxic gases building up. This also lets birds have a drink and allows more oxygen to get into the water, supporting amphibious life. If snow falls onto the ice, brush it off to allow maximum light through so that plant life can continue to grow. Read my article on looking after winter wildlife here.